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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 fetch_github_activity(gen, metadata):
 """ registered handler for the github activity plugin it puts in generator.context the html needed to be displayed on a template """


    if 'GITHUB_ACTIVITY_FEED' in gen.settings.keys():
        gen.context['github_activity'] = gen.plugin_instance.fetch()