code: def _retype(self, maxnum):
      if maxnum < 2**16:
          newtype = "H"
      elif maxnum < 2**31:
          newtype = "i"
      elif maxnum < 2**32:
          newtype = "I"
      elif self._allow_longs:
          newtype = "q"
      else:
          raise OverflowError(
              "%r is too big to fit in an array" % maxnum
          )
  
      try:
          self.array = array(newtype, iter(self.array))
      except ValueError:
          self.array = list(self.array)
  
imports: from array import array
  from whoosh.compat import xrange
  from whoosh.system import emptybytes
  from whoosh.system import pack_byte, unpack_byte
  from whoosh.system import pack_ushort_le, unpack_ushort_le
  from whoosh.system import pack_uint_le, unpack_uint_le
label_desc: Use image node_id 5 for calling the GrowableArray obj's underlying member method code with example usage: obj._retype(maxnum) without return types