def METHOD_NAME(self, line):
    """
    A helper method for inserting a line, handling color automatically, into the graph.
    Args:
        line[chigger.graph.Line]: The line object to add to this graph.
    """
    # Initialize the line (this creates the vtk object)
    if line.needsInitialize():
        line.initialize()
    # Set the line color, if not set by the user
    if not line.isOptionValid('color'):
        # Colors
        if self._vtkcolorseries is None:
            self._vtkcolorseries = vtk.vtkColorSeries()
            if self.isOptionValid('color_scheme'):
                scheme = eval('vtk.vtkColorSeries.' + self.getOption('color_scheme').upper())
                self._vtkcolorseries.SetColorScheme(scheme)
        n_lines = len(self._plots)
        n_colors = self._vtkcolorseries.GetNumberOfColors()
        if n_lines >= n_colors:
            mooseutils.mooseWarning('The number of lines exceeds the number of available '
                                    'line colors.')
        c = self._vtkcolorseries.GetColorRepeating(n_lines)
        b = self.getOption('background')
        # If the color matches the background, flip it
        if (c[0] == b[0]) and (c[1] == b[1]) and (c[2] == c[2]):
            c[0] = 1 - c[0]
            c[1] = 1 - c[1]
            c[2] = 1 - c[2]
        line.setOption('color', c)
    self._plots.append(line)