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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 _get_call_names_helper(node):
 """Recursively finds all function names."""

    if isinstance(node, ast.Name):
        if node.id not in BLACK_LISTED_CALL_NAMES:
            yield node.id
    elif isinstance(node, ast.Subscript):
        yield from _get_call_names_helper(node.value)
    elif isinstance(node, ast.Str):
        yield node.s
    elif isinstance(node, ast.Attribute):
        yield node.attr
        yield from _get_call_names_helper(node.value)