How to use the proplot.utils._default function in proplot

def _spaces_as_ratios(self,
            hspace=None, wspace=None, # spacing between axes
            height_ratios=None, width_ratios=None,
            **kwargs):
        """For keyword arg usage, see `FlexibleGridSpecBase`."""
        # Parse flexible input
        nrows = self._nrows_visible
        ncols = self._ncols_visible
        hratios = np.atleast_1d(_default(height_ratios, 1))
        wratios = np.atleast_1d(_default(width_ratios,  1))
        hspace = np.atleast_1d(_default(hspace, np.mean(hratios)*0.10)) # this is relative to axes
        wspace = np.atleast_1d(_default(wspace, np.mean(wratios)*0.10))
        if len(wspace)==1:
            wspace = np.repeat(wspace, (ncols-1,)) # note: may be length 0
        if len(hspace)==1:
            hspace = np.repeat(hspace, (nrows-1,))
        if len(wratios)==1:
            wratios = np.repeat(wratios, (ncols,))
        if len(hratios)==1:
            hratios = np.repeat(hratios, (nrows,))

        # Verify input ratios and spacings
        # Translate height/width spacings, implement as extra columns/rows
        if len(hratios) != nrows:
            raise ValueError(f'Got {nrows} rows, but {len(hratios)} hratios.')
        if len(wratios) != ncols:
            raise ValueError(f'Got {ncols} columns, but {len(wratios)} wratios.')
        if ncols>1 and len(wspace) != ncols-1:

axwidth  = units(axwidth)
    axheight = units(axheight)
    # Gridspec defaults
    # NOTE: Ratios are scaled to take physical units in _subplots_kwargs, so
    # user can manually provide hspace and wspace in physical units.
    hspace = np.atleast_1d(units(_default(hspace,
        rc['subplot.titlespace'] + rc['subplot.innerspace'] if sharex==3
        else rc['subplot.xlabspace'] if sharex in (1,2) # space for tick labels and title
        else rc['subplot.titlespace'] + rc['subplot.xlabspace'])))
    wspace = np.atleast_1d(units(_default(wspace,
        rc['subplot.innerspace'] if sharey==3
        else rc['subplot.ylabspace'] - rc['subplot.titlespace'] if sharey in (1,2) # space for tick labels only
        else rc['subplot.ylabspace']
        )))
    wratios = np.atleast_1d(_default(width_ratios, wratios, axwidths, 1))
    hratios = np.atleast_1d(_default(height_ratios, hratios, axheights, 1))
    if len(wspace)==1:
        wspace = np.repeat(wspace, (ncols-1,))
    if len(hspace)==1:
        hspace = np.repeat(hspace, (nrows-1,))
    if flush or wflush:
        wspace = wspace*0.0
    if flush or hflush:
        hspace = hspace*0.0
    if len(wratios)==1:
        wratios = np.repeat(wratios, (ncols,))
    if len(hratios)==1:
        hratios = np.repeat(hratios, (nrows,))
    left   = units(_default(left,   rc['subplot.ylabspace']))
    bottom = units(_default(bottom, rc['subplot.xlabspace']))
    right  = units(_default(right,  rc['subplot.nolabspace']))
    top    = units(_default(top,    rc['subplot.titlespace']))

xgridminor = _default(xgridminor, grid and axis in ('x','both') and which in ('minor','both'))
            ygridminor = _default(ygridminor, grid and axis in ('y','both') and which in ('minor','both'))

        # Weird bug override
        # NOTE: Latest matplotlib versions seem to have fixed below bug. For
        # now remove warning message, because it is triggered whenever user
        # draws a top 'flush' panel.
        # if xticklabelloc in ('both','top') and (xlabelloc!='top' or not xlabel): # xtickloc *cannot* be 'top', *only* appears for 'both'
        #     warnings.warn('This keyword combo causes matplotlib bug where title is not offset from tick labels. Try again with xticklabelloc="bottom" or xlabelloc="top". Defaulting to the latter.')
        #     xticklabelloc = xlabelloc = 'top'
        # Sensible defaults for spine, tick, tick label, and label locations
        # NOTE: Allow tick labels to be present without ticks! User may
        # want this sometimes! Same goes for spines!
        xspineloc     = _default(xloc, xspineloc)
        yspineloc     = _default(yloc, yspineloc)
        xtickloc      = _default(xtickloc, xspineloc, _rcloc_to_stringloc('x', 'xtick'))
        ytickloc      = _default(ytickloc, yspineloc, _rcloc_to_stringloc('y', 'ytick'))
        xspineloc     = _default(xspineloc, _rcloc_to_stringloc('x', 'axes.spines'))
        yspineloc     = _default(yspineloc, _rcloc_to_stringloc('y', 'axes.spines'))
        xticklabelloc = _default(xticklabelloc, xtickloc)
        yticklabelloc = _default(yticklabelloc, ytickloc)
        xlabelloc     = _default(xlabelloc, xticklabelloc)
        ylabelloc     = _default(ylabelloc, yticklabelloc)
        if xlabelloc not in (None,'bottom','top'): # e.g. 'both' or 'neither'
            xlabelloc = 'bottom'
        if ylabelloc not in (None,'left','right'):
            ylabelloc = 'left'

        # Begin loop
        for (axis, label, color, ticklen, margin,
            tickloc, spineloc, ticklabelloc, labelloc,
            bounds, grid, gridminor, tickminor, tickminorlocator,

def _spaces_as_ratios(self,
            hspace=None, wspace=None, # spacing between axes
            height_ratios=None, width_ratios=None,
            **kwargs):
        """For keyword arg usage, see `FlexibleGridSpecBase`."""
        # Parse flexible input
        nrows = self._nrows_visible
        ncols = self._ncols_visible
        hratios = np.atleast_1d(_default(height_ratios, 1))
        wratios = np.atleast_1d(_default(width_ratios,  1))
        hspace = np.atleast_1d(_default(hspace, np.mean(hratios)*0.10)) # this is relative to axes
        wspace = np.atleast_1d(_default(wspace, np.mean(wratios)*0.10))
        if len(wspace)==1:
            wspace = np.repeat(wspace, (ncols-1,)) # note: may be length 0
        if len(hspace)==1:
            hspace = np.repeat(hspace, (nrows-1,))
        if len(wratios)==1:
            wratios = np.repeat(wratios, (ncols,))
        if len(hratios)==1:
            hratios = np.repeat(hratios, (nrows,))

        # Verify input ratios and spacings
        # Translate height/width spacings, implement as extra columns/rows
        if len(hratios) != nrows:
            raise ValueError(f'Got {nrows} rows, but {len(hratios)} hratios.')
        if len(wratios) != ncols:
            raise ValueError(f'Got {ncols} columns, but {len(wratios)} wratios.')
        if ncols>1 and len(wspace) != ncols-1:

ytickminor    = _default(ytickminor, rc['ytick.minor.visible'])
        xformatter    = _default(xticklabels, xformatter) # default is just matplotlib version
        yformatter    = _default(yticklabels, yformatter)
        xlocator      = _default(xticks, xlocator) # default is AutoLocator, no setting
        ylocator      = _default(yticks, ylocator)
        xminorlocator = _default(xminorticks, xminorlocator) # default is AutoMinorLocator, no setting
        yminorlocator = _default(yminorticks, yminorlocator)
        # Grid defaults are more complicated
        axis = rc.get('axes.grid.axis') # always need this property
        grid, which = rc['axes.grid'], rc['axes.grid.which']
        if which is not None or grid is not None: # only if *one* was changed recently!
            if grid is None:
                grid = rc.get('axes.grid')
            elif which is None:
                which = rc.get('axes.grid.which')
            xgrid      = _default(xgrid, grid and axis in ('x','both') and which in ('major','both'))
            ygrid      = _default(ygrid, grid and axis in ('y','both') and which in ('major','both'))
            xgridminor = _default(xgridminor, grid and axis in ('x','both') and which in ('minor','both'))
            ygridminor = _default(ygridminor, grid and axis in ('y','both') and which in ('minor','both'))

        # Weird bug override
        # NOTE: Latest matplotlib versions seem to have fixed below bug. For
        # now remove warning message, because it is triggered whenever user
        # draws a top 'flush' panel.
        # if xticklabelloc in ('both','top') and (xlabelloc!='top' or not xlabel): # xtickloc *cannot* be 'top', *only* appears for 'both'
        #     warnings.warn('This keyword combo causes matplotlib bug where title is not offset from tick labels. Try again with xticklabelloc="bottom" or xlabelloc="top". Defaulting to the latter.')
        #     xticklabelloc = xlabelloc = 'top'
        # Sensible defaults for spine, tick, tick label, and label locations
        # NOTE: Allow tick labels to be present without ticks! User may
        # want this sometimes! Same goes for spines!
        xspineloc     = _default(xloc, xspineloc)
        yspineloc     = _default(yloc, yspineloc)

nrows = array.shape[0]
    ncols = array.shape[1]

    #--------------------------------------------------------------------------#
    # Panels
    #--------------------------------------------------------------------------#
    # Parse outer panel kwargs, consolidate settings
    for ipanel in (panel,legend,colorbar):
        for side in (ipanel or ''):
            if side + 'array' in kwargs:
                kwargs[side + 'span'] = kwargs.pop(side + 'array')
            elif side + 'span' not in kwargs:
                kwargs[side + 'span'] = True # spans all rows or columns
    panels    = _default(panel, panels, '')
    legends   = _default(legend, legends, '')
    colorbars = _default(colorbar, colorbars, '')
    # Get panel props
    kwargs = _panels_kwargs(panels, colorbars, legends, kwargs,
        ncols=ncols, nrows=nrows, figure=True)
    # Warnings
    axpanels    = _default(axpanel, axpanels, '')
    axcolorbars = _default(axcolorbar, axcolorbars, '')
    axlegends   = _default(axlegend, axlegends, '')
    axpanels_kw    = _default(axpanel_kw, axpanels_kw, {})
    axcolorbars_kw = _default(axcolorbar_kw, axcolorbars_kw, {})
    axlegends_kw   = _default(axlegend_kw, axlegends_kw, {})
    if not axpanels and axpanels_kw:
        warnings.warn(f'Ignoring axpanels keyword args: {axpanels_kw}')
    if not axcolorbars and axcolorbars_kw:
        warnings.warn(f'Ignoring axcolorbars keyword args: {axcolorbars_kw}')
    if not axlegends and axlegends_kw:
        warnings.warn(f'Ignoring axlegends keyword args: {axlegends_kw}')

yformatter    = _default(yticklabels, yformatter)
        xlocator      = _default(xticks, xlocator) # default is AutoLocator, no setting
        ylocator      = _default(yticks, ylocator)
        xminorlocator = _default(xminorticks, xminorlocator) # default is AutoMinorLocator, no setting
        yminorlocator = _default(yminorticks, yminorlocator)
        # Grid defaults are more complicated
        axis = rc.get('axes.grid.axis') # always need this property
        grid, which = rc['axes.grid'], rc['axes.grid.which']
        if which is not None or grid is not None: # only if *one* was changed recently!
            if grid is None:
                grid = rc.get('axes.grid')
            elif which is None:
                which = rc.get('axes.grid.which')
            xgrid      = _default(xgrid, grid and axis in ('x','both') and which in ('major','both'))
            ygrid      = _default(ygrid, grid and axis in ('y','both') and which in ('major','both'))
            xgridminor = _default(xgridminor, grid and axis in ('x','both') and which in ('minor','both'))
            ygridminor = _default(ygridminor, grid and axis in ('y','both') and which in ('minor','both'))

        # Weird bug override
        # NOTE: Latest matplotlib versions seem to have fixed below bug. For
        # now remove warning message, because it is triggered whenever user
        # draws a top 'flush' panel.
        # if xticklabelloc in ('both','top') and (xlabelloc!='top' or not xlabel): # xtickloc *cannot* be 'top', *only* appears for 'both'
        #     warnings.warn('This keyword combo causes matplotlib bug where title is not offset from tick labels. Try again with xticklabelloc="bottom" or xlabelloc="top". Defaulting to the latter.')
        #     xticklabelloc = xlabelloc = 'top'
        # Sensible defaults for spine, tick, tick label, and label locations
        # NOTE: Allow tick labels to be present without ticks! User may
        # want this sometimes! Same goes for spines!
        xspineloc     = _default(xloc, xspineloc)
        yspineloc     = _default(yloc, yspineloc)
        xtickloc      = _default(xtickloc, xspineloc, _rcloc_to_stringloc('x', 'xtick'))
        ytickloc      = _default(ytickloc, yspineloc, _rcloc_to_stringloc('y', 'ytick'))

def _panel_prop(side, name, defaults):
        """Returns property from the appropriate dictionary, or returns the
        default from the rc.subplots category."""
        if not isinstance(defaults, tuple):
            defaults = 3*(defaults,)
        for check,kwargs,default in zip((panels, colorbars, legends), (panels_kw, colorbars_kw, legends_kw), defaults):
            if side not in check:
                continue
            if isinstance(default, str):
                default = rc['subplot.' + default]
            return _default(kwargs.get(name, None), kwargs.get(side + name, None), default)

`~matplotlib.axes.Axes.legend`. Defaults to ``rc['colorbar.frameon']``.
        alpha, linewidth, edgecolor, facecolor : optional
            Transparency, edge width, edge color, and face color for the frame.
            Defaults to ``rc['colorbar.framealpha']``, ``rc['axes.linewidth']``,
            ``rc['axes.edgecolor']``, and ``rc['axes.facecolor']``.
        **kwargs
            Passed to `~proplot.wrappers.colorbar_wrapper`.
        """
        # Location
        ax, loc = wrappers._get_panel(self, loc)
        if loc=='fill':
            return ax.colorbar(*args, **kwargs)
        # Default props
        loc = _default(loc, rc['colorbar.loc'])
        extend = units(_default(kwargs.get('extendsize',None), rc['colorbar.extendinset']))
        length = units(_default(length, rc['colorbar.length']))/self.width
        width = units(_default(width, rc['colorbar.width']))/self.height
        pad = units(_default(pad, rc['colorbar.axespad']))
        xpad = pad/self.width
        ypad = pad/self.height
        # Space for labels
        if kwargs.get('label', ''):
            xspace = 2.4*rc['font.size']/72 + rc['xtick.major.size']/72
        else:
            xspace = 1.2*rc['font.size']/72 + rc['xtick.major.size']/72
        xspace /= self.height
        # Get location in axes-relative coordinates
        # Bounds are x0, y0, width, height in axes-relative coordinate to start
        if loc in ('upper right','ur'):
            bounds = (1-xpad-length, 1-ypad-width)
            fbounds = (1-2*xpad-length, 1-2*ypad-width-xspace)
        elif loc in ('upper left','ul'):