Geometry builders that can integrate another geometry into their own are called composite geometry builders, those that do not are called non-composite. Note that the composite, non-composite qualifiers do not refer to the type of geometry that the builder constructs, instead, they refer to whether or not the builder is capable of integrating another geometry into its own.
Usually, the builders that construct aggregate geometries are composite geometry builders. One can envisage a custom non-composite geometry builder that builds an aggregate geometry. For example, if a multi-point feature in the input XML document is defined to be something like:
<multi-point dimension="2"> 2.3,34.9 445.4,34.34 23.35,345.453 </multi-point>
A custom geometry builder used solely to build an aggregate of point features out of the <multi-point> element does not need to be a composite geometry builder, since it does not need to accept a point geometry from other builders because the information for all of the point components are embedded in the <multi-point> element’s text content.