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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 is_simple(fun):
 """A heuristic to find out if a function is simple enough."""

    seen_load_fast_0 = False
    seen_load_response = False
    seen_call_fun = False

    for instruction in dis.get_instructions(fun):
        if instruction.opname == 'LOAD_FAST' and instruction.arg == 0:
            seen_load_fast_0 = True
            continue

        if instruction.opname == 'LOAD_ATTR' \
           and instruction.argval == 'Response':
            seen_load_response = True
            continue

        if instruction.opname.startswith('CALL_FUNCTION'):
            if seen_call_fun:
                return False

            seen_call_fun = True
            continue

    return seen_call_fun and seen_load_fast_0 and seen_load_response