code: func (st *FieldInvertState) reset() {
  	st.position = -1
  	st.length = 0
  	st.numOverlap = 0
  	st.offset = 0
  	st.maxTermFrequency = 0
  	st.uniqueTermCount = 0
  	st.boost = 1.0
  	st.lastStartOffset = 0
  	st.lastPosition = 0
  }
docs: /* Re-initialize the state */