class RuboCop::Cop::Lint::ShadowedArgument

def check_argument(argument)
  return unless argument.method_argument? || argument.block_argument?
  # Block local variables, i.e., variables declared after ; inside
  # |...| aren't really arguments.
  return if argument.explicit_block_local_variable?
  shadowing_assignment(argument) do |node|
    message = format(MSG, argument: argument.name)
    add_offense(node, message: message)
  end
end