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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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)