class RuboCop::Cop::Style::LineEndConcatenation

def check_token_set(index)
  predecessor, operator, successor = processed_source.tokens[index, 3]
  return unless eligible_successor?(successor) &&
                eligible_operator?(operator) &&
                eligible_predecessor?(predecessor)
  return if operator.pos.line == successor.pos.line
  next_successor = token_after_last_string(successor, index)
  return unless eligible_next_successor?(next_successor)
  add_offense(operator.pos, operator.pos)
end