B (final java.lang.Iterable<? extends Number> extendsGenerics) { if (extendsGenerics == null) { throw new java.lang.NullPointerException("extendsGenerics cannot be null"); } if (this.extendsGenerics == null) this.extendsGenerics = com.google.common.collect.ImmutableSet.builder(); this.extendsGenerics.addAll(extendsGenerics); return self(); }