How to use the pyproj.exceptions.CRSError function in pyproj

def test_crs_exception():
    with pytest.raises(CRSError, match="Internal Proj Error"):
        CRS("+proj=bobbyjoe")

def test_cf_from_invalid():
    with pytest.raises(CRSError):
        CRS.from_cf(
            dict(
                longitude_of_central_meridian=265.0, latitude_of_projection_origin=25.0
            )
        )

    with pytest.raises(CRSError):
        CRS.from_cf(
            dict(grid_mapping_name="invalid", latitude_of_projection_origin=25.0)
        )

def test_cf_from_invalid():
    with pytest.raises(CRSError):
        CRS.from_cf(
            dict(
                longitude_of_central_meridian=265.0, latitude_of_projection_origin=25.0
            )
        )

    with pytest.raises(CRSError):
        CRS.from_cf(
            dict(grid_mapping_name="invalid", latitude_of_projection_origin=25.0)
        )

def _prepare_from_string(in_crs_string):
    if not in_crs_string:
        raise CRSError("CRS is empty or invalid: {!r}".format(in_crs_string))
    elif "{" in in_crs_string:
        # may be json, try to decode it
        try:
            crs_dict = json.loads(in_crs_string, strict=False)
        except ValueError:
            raise CRSError("CRS appears to be JSON but is not valid")

        if not crs_dict:
            raise CRSError("CRS is empty JSON")
        return _prepare_from_dict(crs_dict)
    elif is_proj(in_crs_string):
        in_crs_string = re.sub(r"[\s+]?=[\s+]?", "=", in_crs_string.lstrip())
        # make sure the projection starts with +proj or +init
        starting_params = ("+init", "+proj", "init", "proj")
        if not in_crs_string.startswith(starting_params):
            kvpairs = []
            first_item_inserted = False
            for kvpair in in_crs_string.split():
                if not first_item_inserted and (kvpair.startswith(starting_params)):
                    kvpairs.insert(0, kvpair)
                    first_item_inserted = True
                else:
                    kvpairs.append(kvpair)
            in_crs_string = " ".join(kvpairs)

def _prepare_from_string(in_crs_string):
    if not in_crs_string:
        raise CRSError("CRS is empty or invalid: {!r}".format(in_crs_string))
    elif "{" in in_crs_string:
        # may be json, try to decode it
        try:
            crs_dict = json.loads(in_crs_string, strict=False)
        except ValueError:
            raise CRSError("CRS appears to be JSON but is not valid")

        if not crs_dict:
            raise CRSError("CRS is empty JSON")
        return _prepare_from_dict(crs_dict)
    elif is_proj(in_crs_string):
        in_crs_string = re.sub(r"[\s+]?=[\s+]?", "=", in_crs_string.lstrip())
        # make sure the projection starts with +proj or +init
        starting_params = ("+init", "+proj", "init", "proj")
        if not in_crs_string.startswith(starting_params):
            kvpairs = []
            first_item_inserted = False
            for kvpair in in_crs_string.split():
                if not first_item_inserted and (kvpair.startswith(starting_params)):
                    kvpairs.insert(0, kvpair)
                    first_item_inserted = True
                else:

False
        """
        if isinstance(projparams, str):
            projstring = _prepare_from_string(projparams)
        elif isinstance(projparams, dict):
            projstring = _prepare_from_dict(projparams)
        elif kwargs:
            projstring = _prepare_from_dict(kwargs)
        elif isinstance(projparams, int):
            projstring = _prepare_from_epsg(projparams)
        elif isinstance(projparams, (list, tuple)) and len(projparams) == 2:
            projstring = _prepare_from_authority(*projparams)
        elif hasattr(projparams, "to_wkt"):
            projstring = projparams.to_wkt()
        else:
            raise CRSError("Invalid CRS input: {!r}".format(projparams))

        super(CRS, self).__init__(projstring)

def _prepare_from_string(in_crs_string):
    if not in_crs_string:
        raise CRSError("CRS is empty or invalid: {!r}".format(in_crs_string))
    elif "{" in in_crs_string:
        # may be json, try to decode it
        try:
            crs_dict = json.loads(in_crs_string, strict=False)
        except ValueError:
            raise CRSError("CRS appears to be JSON but is not valid")

        if not crs_dict:
            raise CRSError("CRS is empty JSON")
        return _prepare_from_dict(crs_dict)
    elif is_proj(in_crs_string):
        in_crs_string = re.sub(r"[\s+]?=[\s+]?", "=", in_crs_string.lstrip())
        # make sure the projection starts with +proj or +init
        starting_params = ("+init", "+proj", "init", "proj")
        if not in_crs_string.startswith(starting_params):
            kvpairs = []

----------
        other: Any
            Check if the other object is equivalent to this object.
            If the other object is not a CRS, it will try to create one.
            On Failure, it will return False.
        ignore_axis_order: bool, optional
            If True, it will compare the CRS class and ignore the axis order.
            Default is False.

        Returns
        -------
        bool
        """
        try:
            other = CRS.from_user_input(other)
        except CRSError:
            return False
        return super(CRS, self).equals(other, ignore_axis_order=ignore_axis_order)

grid_mapping_variable = None
    variable_is_itself_gridmapping = False
    # test if the variable has a grid_mapping attribute
    if hasattr(nc_handle[variable], 'grid_mapping'):
        # good. attempt to load the grid_mapping information into a pyproj object
        crs = _load_crs_from_cf_gridmapping(nc_handle, nc_handle[variable].grid_mapping)
        grid_mapping_variable = nc_handle[variable].grid_mapping
    elif hasattr(nc_handle[variable], 'grid_mapping_name') and \
            nc_handle[variable].grid_mapping_name in _valid_cf_type_of_grid_mapping:
        # this looks like a valid grid_mapping variable
        try:
            # try to load it
            crs = _load_crs_from_cf_gridmapping(nc_handle, variable)
            grid_mapping_variable = variable
            variable_is_itself_gridmapping = True
        except pyproj.exceptions.CRSError as ex:
            raise ValueError("ERROR: pyproj didn't manage to load the CRS: {}".format(ex))
    else:
        # fallback position: maybe the variable is on a basic lat/lon grid with no
        #   grid_mapping. Note: there is no default CRS in CF, we choose WGS84
        grid_mapping_variable = "latlon_default"
        crs = pyproj.CRS.from_string('+proj=latlon +datum=WGS84 +ellps=WGS84')

    # return
    return crs, grid_mapping_variable, variable_is_itself_gridmapping