code: def _parse_param(key, val):
      
  
      regex = re.compile(r'fields\[([A-Za-z]+)\]')
      match = regex.match(key)
  
      if match:
          if not isinstance(val, list):
              val = val.split(',')
  
          fields = [field.lower() for field in val]
          rtype = match.groups()[0].lower()
  
          return rtype, fields
docs: Parse the query param looking for sparse fields params
  
      Ensure the `val` or what will become the sparse fields
      is always an array. If the query param is not a sparse
      fields query param then return None.
  
      :param key:
          the query parameter key in the request (left of =)
      :param val:
          the query parameter val in the request (right of =)
      :return:
          tuple of resource type to implement the sparse
          fields on & a array of the fields.