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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 get_id_count(search_term):
 """Get the number of citations in Pubmed for a search query. Parameters search_term : str A term for which the PubMed search should be performed. Returns ------- int or None The number of citations for the query, or None if the query fails. """

    params = {'term': search_term,
              'rettype': 'count',
              'db': 'pubmed'}
    tree = send_request(pubmed_search, params)
    if tree is None:
        return None
    else:
        count = tree.getchildren()[0].text
        return int(count)