code: public AddToTextIndexRequestBuilder addReferencePrefixes(final String referencePrefix, final String... referencePrefixes) {
          this.referencePrefixes.add(referencePrefix);
          this.referencePrefixes.addAll(Arrays.asList(referencePrefixes));
  
          return this;
      }
docs: Adds values to the referencePrefixes parameter
  
  @param referencePrefix   The first index
  @param referencePrefixes The remaining referencePrefixes
  @return this