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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 _GetFieldPathElementIndex(api_error, field):
 """Retrieve the index of a given field in the api_error's fieldPathElements. Args: api_error: a dict containing a partialFailureError returned from the AdWords API. field: a str field for which this determines the index in the api_error's fieldPathElements. Returns: An int index of the field path element, or None if the specified field can't be found in the api_error. """

  field_path_elements = api_error['fieldPathElements']

  if field_path_elements:
    found_index = [field_path_element['index']
                   for field_path_element in field_path_elements
                   if field_path_element['field'] == field]
    if found_index:
      return found_index

  return None