async def load_varint(reader):
buffer = _UINT_BUFFER<EOL>await reader.areadinto(buffer)<EOL>width = int_mark_to_size(buffer[<NUM_LIT:0>] & PortableRawSizeMark.MASK)<EOL>result = buffer[<NUM_LIT:0>]<EOL>shift = <NUM_LIT:8><EOL>for _ in range(width-<NUM_LIT:1>):<EOL><INDENT>await reader.areadinto(buffer)<EOL>result += buffer[<NUM_LIT:0>] << shift<EOL>shift += <NUM_LIT:8><EOL><DEDENT>return result >> <NUM_LIT:2><EOL>
Binary load of variable size integer serialized by dump_varint

:param reader:
:return: