How to use the gitdb.utils.compat.buffer function in gitdb

def offsets(self):
        """:return: sequence of all offsets in the order in which they were written

        **Note:** return value can be random accessed, but may be immmutable"""
        if self._version == 2:
            # read stream to array, convert to tuple
            a = array.array('I')    # 4 byte unsigned int, long are 8 byte on 64 bit it appears
            a.fromstring(buffer(self._cursor.map(), self._pack_offset, self._pack_64_offset - self._pack_offset))

            # networkbyteorder to something array likes more
            if sys.byteorder == 'little':
                a.byteswap()
            return a
        else:
            return tuple(self.offset(index) for index in xrange(self.size()))
        # END handle version

def delta_chunk_apply(dc, bbuf, write):
    """Apply own data to the target buffer
    :param bbuf: buffer providing source bytes for copy operations
    :param write: write method to call with data to write"""
    if dc.data is None:
        # COPY DATA FROM SOURCE
        write(buffer(bbuf, dc.so, dc.ts))
    else:
        # APPEND DATA
        # whats faster: if + 4 function calls or just a write with a slice ?
        # Considering data can be larger than 127 bytes now, it should be worth it
        if dc.ts < len(dc.data):
            write(dc.data[:dc.ts])
        else:
            write(dc.data)
        # END handle truncation

def offsets(self):
        """:return: sequence of all offsets in the order in which they were written

        **Note:** return value can be random accessed, but may be immmutable"""
        if self._version == 2:
            # read stream to array, convert to tuple
            a = array.array('I')    # 4 byte unsigned int, long are 8 byte on 64 bit it appears
            a.fromstring(buffer(self._cursor.map(), self._pack_offset, self._pack_64_offset - self._pack_offset))

            # networkbyteorder to something array likes more
            if sys.byteorder == 'little':
                a.byteswap()
            return a
        else:
            return tuple(self.offset(index) for index in xrange(self.size()))
        # END handle version