code: def _integerValue_to_int(value_str):
      
      m = BINARY_VALUE.match(value_str)
      if m:
          value = int(m.group(1), 2)
      elif OCTAL_VALUE.match(value_str):
          value = int(value_str, 8)
      elif DECIMAL_VALUE.match(value_str):
          value = int(value_str)
      elif HEX_VALUE.match(value_str):
          value = int(value_str, 16)
      else:
          value = None
      return value
docs: Convert a value string that conforms to DSP0004 `integerValue`, into
      the corresponding integer and return it. The returned value has Python
      type `int`, or in Python 2, type `long` if needed.
  
      Note that DSP0207 and DSP0004 only allow US-ASCII decimal digits. However,
      the Python `int()` function supports all Unicode decimal digits (e.g.
      US-ASCII digits, ARABIC-INDIC digits, superscripts, subscripts) and raises
      `ValueError` for non-decimal digits (e.g. Kharoshthi digits).
      Therefore, the match patterns explicitly check for US-ASCII digits, and
      the `int()` function should never raise `ValueError`.
  
      Returns `None` if the value string does not conform to `integerValue`.