code: func (q *DisMaxQuery) TieBreaker(tieBreaker float64) *DisMaxQuery {
  	q.tieBreaker = &tieBreaker
  	return q
  }
docs: // TieBreaker is the factor by which the score of each non-maximum disjunct
  // for a document is multiplied with and added into the final score.
  //
  // If non-zero, the value should be small, on the order of 0.1, which says
  // that 10 occurrences of word in a lower-scored field that is also in a
  // higher scored field is just as good as a unique word in the lower scored
  // field (i.e., one that is not in any higher scored field).