def process_bytecode(link_refs: Dict[str, Any], bytecode: bytes) -> str:
    """
    Replace link_refs in bytecode with 0's.
    """
    all_offsets = [y for x in link_refs.values() for y in x.values()]
    # Link ref validation.
    validate_link_ref_fns = (
        validate_link_ref(ref["start"] * 2, ref["length"] * 2)
        for ref in concat(all_offsets)
    )
    pipe(bytecode, *validate_link_ref_fns)
    # Convert link_refs in bytecode to 0's
    link_fns = (
        replace_link_ref_in_bytecode(ref["start"] * 2, ref["length"] * 2)
        for ref in concat(all_offsets)
    )
    processed_bytecode = pipe(bytecode, *link_fns)
    return add_0x_prefix(processed_bytecode)
Replace link_refs in bytecode with 0's.