def plot_legend(ax, no_legend=True, legend_arg=None):
legend_arg = dict_if_none(legend_arg)<EOL>if not no_legend:<EOL><INDENT>ax.legend(**legend_arg)<EOL><DEDENT>
Function that defines the legend options
of a matplotlib plot.

Args:
    ax: matplotlib axes
    no_legend (bool): Defines the presence of a legend in the figure
    legend_arg (dict): Addition arguments for matplotlib.legend() call