static setGridSampler(newGridSampler) {
			GridSamplerInstance.gridSampler = newGridSampler;
		}
Sets the implementation of GridSampler used by the library. One global
instance is stored, which may sound problematic. But, the implementation provided
ought to be appropriate for the entire platform, and all uses of this library
in the whole lifetime of the JVM. For instance, an Android activity can swap in
an implementation that takes advantage of native platform libraries.

@param newGridSampler The platform-specific object to install.