code: @Nonnull
    public T set(
        @Nonnull DocumentReference documentReference,
        @Nonnull Map<String, Object> fields,
        @Nonnull SetOptions options) {
      return performSet(documentReference, fields, options);
    }
docs: Overwrites the document referred to by this DocumentReference. If the document doesn't exist
  yet, it will be created. If you pass {@link SetOptions}, the provided data can be merged into
  an existing document.
  
  @param documentReference The DocumentReference to overwrite.
  @param fields A map of the field paths and values for the document.
  @param options An object to configure the set behavior.
  @return The instance for chaining.