question: returns the name of the field . could return null if the sort is by score or doc . concode_field_sep SortField FIELD_DOC concode_elem_sep SortField FIELD_SCORE concode_elem_sep Object missingValue concode_elem_sep Comparator<BytesRef> bytesComparator concode_elem_sep boolean reverse concode_elem_sep String field concode_elem_sep Object STRING_FIRST concode_elem_sep FieldComparatorSource comparatorSource concode_elem_sep Type type concode_elem_sep Object STRING_LAST concode_field_sep FieldComparator<?> getComparator concode_elem_sep FieldComparatorSource getComparatorSource concode_elem_sep void initFieldType concode_elem_sep void setBytesComparator concode_elem_sep SortField rewrite concode_elem_sep void setMissingValue concode_elem_sep Comparator<BytesRef> getBytesComparator concode_elem_sep Object getMissingValue concode_elem_sep Type getType concode_elem_sep int hashCode concode_elem_sep boolean getReverse concode_elem_sep boolean equals concode_elem_sep boolean needsScores concode_elem_sep String toString concode_elem_sep String toString concode_elem_sep String toString
target: String function ( ) { return field ; }