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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def pelican_init(pelicanobj):
 global global_siteurl global_siteurl = pelicanobj.settings['SITEURL'] """ Prepare configurations for the MD plugin """

    try:
        import markdown
        from .plantuml_md import PlantUMLMarkdownExtension
    except:
        # Markdown not available
        logger.debug("[plantuml] Markdown support not available")
        return

    # Register the Markdown plugin
    config = { 'siteurl': pelicanobj.settings['SITEURL'] }

    try:
        if 'MD_EXTENSIONS' in pelicanobj.settings.keys(): # pre pelican 3.7.0
            pelicanobj.settings['MD_EXTENSIONS'].append(PlantUMLMarkdownExtension(config))
        elif 'MARKDOWN' in pelicanobj.settings.keys() and \
             not ('extension_configs' in pelicanobj.settings['MARKDOWN']['extension_configs']):  # from pelican 3.7.0
            pelicanobj.settings['MARKDOWN']['extension_configs']['plantuml.plantuml_md'] = {}
    except:
        logger.error("[plantuml] Unable to configure plantuml markdown extension")