public boolean hasItemAt(int index) {
                adjustIfBackingChanged();
                if (startIndex<0) return false; // Invalid state because of backing changes
                if ( index >= length ) return false;
                if ( index+startIndex >= owner.getItemCount() ) return false;
                return true;
            }
The word to replace by at the given index, or null if none of the phrase words should be replaced
This is either null, or of length <code>length</code>, with null values where nothing should be replaced
container-search/src/main/java/com/yahoo/prelude/querytransform/PhraseMatcher.java