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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 process_file(filename, interval=None, lazy=False):
 """Process a CSXML file for its relevant information. Consider running the fix_csxml_character_encoding.py script in indra/sources/medscan to fix any encoding issues in the input file before processing. Attributes filename : str The csxml file, containing Medscan XML, to process interval : (start, end) or None Select the interval of documents to read, starting with the `start`th document and ending before the `end`th document. If either is None, the value is considered undefined. If the value exceeds the bounds of available documents, it will simply be ignored. lazy : bool If True, the statements will not be generated immediately, but rather a generator will be formulated, and statements can be retrieved by using `iter_statements`. If False, the `statements` attribute will be populated immediately. Default is False. Returns ------- mp : MedscanProcessor A MedscanProcessor object containing extracted statements """

    mp = MedscanProcessor()
    mp.process_csxml_file(filename, interval, lazy)
    return mp