How to use the pycbc.workflow.core.Node function in PyCBC

def create_node(self, parent, tags=None):
        if tags is None:
            tags = []
        node = Node(self)

        node.add_input_opt('--input-file', parent)

        if parent.name.endswith("gz"):
            ext = ".xml.gz"
        else:
            ext = ".xml"

        out_files = FileList([])
        for i in range(self.num_splits):
            curr_tag = 'split%d' % i
            curr_tags = parent.tags + [curr_tag]
            job_tag = parent.description + "_" + self.name.upper()
            out_file = File(parent.ifo_list, job_tag, parent.segment,
                            extension=ext, directory=self.out_dir,
                            tags=curr_tags, store_file=self.retain_files)

execute_now : boolean, optional
        If true, jobs are executed immediately. If false, they are added to the
        workflow to be run later.

    Returns
    --------
    veto_def_file : pycbc.workflow.core.SegFile
        The workflow File object corresponding to this DQ veto file.
    """
    if tags is None:
        tags = []
    seg_valid_seg = segments.segment([start_time,end_time])
    # FIXME: This job needs an internet connection and X509_USER_PROXY
    #        For internet connection, it may need a headnode (ie universe local)
    #        For X509_USER_PROXY, I don't know what pegasus is doing
    node = Node(veto_gen_job)
    node.add_opt('--veto-categories', str(category))
    node.add_opt('--ifo-list', ifo)
    node.add_opt('--gps-start-time', str(start_time))
    node.add_opt('--gps-end-time', str(end_time))
    if tags:
        veto_xml_file_name = "%s-VETOTIME_CAT%d_%s-%d-%d.xml" \
                               %(ifo, category, '_'.join(tags), start_time,
                                 end_time-start_time)
    else:
        veto_xml_file_name = "%s-VETOTIME_CAT%d-%d-%d.xml" \
                         %(ifo, category, start_time, end_time-start_time)
    veto_xml_file_path = os.path.abspath(os.path.join(out_dir,
                                         veto_xml_file_name))
    curr_url = urlunparse(['file', 'localhost',
                           veto_xml_file_path, None, None, None])
    if tags:

def create_node(self, job_segment, input_file):
        node = Node(self)
        node.add_input_arg(input_file)
        node.new_output_file_opt(job_segment, '.xml.gz', '--output',
                                 tags=self.tags, store_file=self.retain_files)
        return node

Returns
    --------
    plot_files : ahope.FileList
        A list of the output files from this stage.
    """

    plot_files = FileList([])

    # create executable
    plotnumtemplates_job = Executable(workflow.cp, 'plotnumtemplates',
                                  'vanilla', workflow.ifos, output_dir, tags)

    for tag in tags:
        # create node
        node = Node(plotnumtemplates_job)
        node.add_opt('--gps-start-time', workflow.analysis_time[0])
        node.add_opt('--gps-end-time', workflow.analysis_time[1])
        node.add_opt('--cache-file', cache_filename)
        node.add_opt('--ifo-times', node.executable.ifo_string)
        node.add_opt('--user-tag', tag.upper()+'_SUMMARY_PLOTS')
        node.add_opt('--output-path', output_dir)
        node.add_opt('--bank-pattern', tmpltbank_cachepattern)
        node.add_opt('--enable-output')

        # add node to workflow
        workflow.add_node(node)

        # make all input_files parents
        #for f in input_files:
        #    dep = dax.Dependency(parent=f.node._dax_node, child=node._dax_node)
        #    workflow._adag.addDependency(dep)

def create_node(self, inj_coinc_file, inj_xml_file, veto_file, veto_name, tags=[]):
        node = Node(self)        
        node.add_input_list_opt('--trigger-file', inj_coinc_file)
        node.add_input_list_opt('--injection-file', inj_xml_file)
        if veto_name is not None:
            node.add_input_opt('--veto-file', veto_file)
        node.add_opt('--segment-name', veto_name)
        node.new_output_file_opt(inj_xml_file[0].segment, '.hdf', '--output-file', 
                                 tags=tags)
        return node

def create_node(self, statmap_file, other_statmap_files, tags=None):
        if tags is None:
            tags = []
        node = Node(self)
        node.add_input_opt('--statmap-file', statmap_file)
        node.add_input_list_opt('--other-statmap-files',
                                other_statmap_files)
        node.new_output_file_opt(statmap_file.segment, '.hdf',
                                 '--output-file', tags=None)

        return node

def create_node(self, parent=None, c_file=None, open_box=False,
                    seg_plot=None, tuning_tags=None, exclusion_tags=None,
                    html_dir=None, tags=None):
        if tags is None:
            tags = []
        node = Node(self)

        node.add_opt('--grb-name', self.cp.get('workflow', 'trigger-name'))
        node.add_opt('--start-time', self.cp.get('workflow', 'trigger-time'))
        node.add_opt('--ra', self.cp.get('workflow', 'ra'))
        node.add_opt('--dec', self.cp.get('workflow', 'dec'))
        node.add_opt('--ifo-tag', self.ifos)

        if tuning_tags is not None:
            node.add_opt('--tuning-injections', ','.join(tuning_tags))

        if exclusion_tags is not None:
            node.add_opt('--exclusion-injections', ','.join(exclusion_tags))

        if seg_plot is not None:
            node.add_opt('--seg-plot', seg_plot.storage_path)

def create_node(self, parent, segment, tags=None):
        if tags is None:
            tags = []
        if not parent:
            raise ValueError("Must provide an input file.")

        node = Node(self)
        node.add_input_opt('--input-file', parent)
        output_file = File(parent.ifo_list, self.exe_name,
                           segment, extension='.xml', store_file=True,
                           directory=self.out_dir, tags=tags)
        node.add_output_opt('--output-file', output_file)

        return node

def create_node(self, job_segment, input_file):
        node = Node(self)
        node.add_input_opt('--database', input_file)
        node.new_output_file_opt(job_segment, '.xml', '--extract',
                                 tags=self.tags, store_file=self.retain_files)
        return node

def create_node(self, job_segment, trigger_files):
        node = Node(self)
        for file in trigger_files:
            node.add_input_arg(file)
        node.new_output_file_opt(job_segment, '.pickle', '--output-file',
                                 tags=self.tags, store_file=self.retain_files)
        return node