code: def remove_leading_spaces(self, input_model):
          
          leading_spaces = 1024
          output_model = []
          for mline in input_model:
              line = mline[0]
              if line.rstrip(' \r\n') != '':
                  leading_spaces = min(leading_spaces, len(line) - len(line.lstrip(' ')))
                  output_model.append([line[leading_spaces:], mline[1]])
  
                  line_len = len(line[leading_spaces:])
                  if line_len > self.max_line_len:
                      self.max_line_len = line_len
              else:
                  output_model.append(['\n', mline[1]])
          return output_model
docs: This function is a part of the model  post-processing pipeline. It
          removes leading spaces from an extracted module; depending on the
          formatting of the draft/rfc text, may have multiple spaces prepended
          to each line. The function also determines the length of the longest
          line in the module - this value can be used by later stages of the
          model post-processing pipeline.
          :param input_model: The YANG model to be processed
          :return: YANG model lines with leading spaces removed