def to_bytes(pool):
        out_stream = ABCFileOutputStream()

        count = len(pool.integers)
        if count <= 1:
            out_stream.writeU30(0)
        else:
            out_stream.writeU30(count)
            for integer in pool.integers[1:]:
                out_stream.writeS32(integer)

        count = len(pool.uintegers)
        if count <= 1:
            out_stream.writeU30(0)
        else:
            out_stream.writeU30(count)
            for uinteger in pool.uintegers[1:]:
                out_stream.writeU32(uinteger)

        count = len(pool.doubles)
        if count <= 1:
            out_stream.writeU30(0)
        else:
            out_stream.writeU30(count)
            for d in pool.doubles[1:]:
                out_stream.writeD64(d)

        count = len(pool._strings)
        if count <= 1:
            out_stream.writeU30(0)
        else:
            out_stream.writeU30(count)
            for s in pool._strings[1:]:
                str_size = len(s)
                out_stream.writeU30(str_size)
                out_stream.write(s)

        count = len(pool._namespaces)
        if count <= 1:
            out_stream.writeU30(0)
        else:
            out_stream.writeU30(count)
            for kind, name in pool._namespaces[1:]:
                out_stream.writeU8(kind)
                out_stream.writeU30(name)

        count = len(pool._ns_sets)
        if count <= 1:
            out_stream.writeU30(0)
        else:
            out_stream.writeU30(count)
            for ns_set in pool._ns_sets[1:]:
                ns_count = len(ns_set)
                out_stream.writeU30(ns_count)
                for ns in ns_set:
                    out_stream.writeU30(ns)

        count = len(pool._multinames)
        if count <= 1:
            out_stream.writeU30(0)
        else:
            out_stream.writeU30(count)
            for multiname in pool._multinames[1:]:
                m_bytes = MultinameConverter.to_bytes(multiname)
                out_stream.write(m_bytes)

        return out_stream.getvalue()