'Return the int value of the four bytes at the file position defined by
self._base_offset + *base* + *offset*. If *base* is None, the long is
read from the current position in the stream. The endian setting of
this instance is used to interpret the byte layout of the long.'

def read_long(self, base, offset=0):

    fmt = ('<L' if (self._byte_order is LITTLE_ENDIAN) else '>L')
    return self._read_int(fmt, base, offset)
