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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 parse_names(cls, expression):
 """Return the list of identifiers used in the expression."""

        names = set()
        try:
            ast_node = ast.parse(expression, "ast")

            class Visitor(ast.NodeVisitor):
                def visit_Name(self, node):
                    names.add(node.id)

            Visitor().visit(ast_node)
        except Exception:
            pass
        return names