class RuboCop::Cop::Performance::RedundantEqualityComparisonBlock

def new_argument(block_argument, block_body)
  if block_argument.source == block_body.receiver.source
    rhs = block_body.first_argument
    return if use_block_argument_in_method_argument_of_operand?(block_argument, rhs)
    rhs.source
  elsif block_argument.source == block_body.first_argument.source
    lhs = block_body.receiver
    return if use_block_argument_in_method_argument_of_operand?(block_argument, lhs)
    lhs.source
  end
end