code: @SuppressWarnings({"WeakerAccess", "unused"}) // For library users
      public Searcher removeNumericRefinement(@NonNull String attribute, @NonNull Integer operator) {
          return removeNumericRefinement(new NumericRefinement(attribute, operator, NumericRefinement.VALUE_UNKNOWN));
      }
docs: Removes the numeric refinement relative to an attribute and operator for the next queries.
  
  @param attribute an attribute that maybe has some refinements.
  @param operator  an {@link NumericRefinement#OPERATOR_EQ operator}.
  @return this {@link Searcher} for chaining.