code: public org.inferred.freebuilder.processor.property.Property.Builder setBoxedType(
        TypeMirror boxedType) {
      this.boxedType = Objects.requireNonNull(boxedType);
      return (org.inferred.freebuilder.processor.property.Property.Builder) this;
    }
docs: Sets the value to be returned by {@link
  org.inferred.freebuilder.processor.property.Property#getBoxedType()}.
  
  @return this {@code Builder} object
  @throws NullPointerException if {@code boxedType} is null