This example shows how to compose d3.forceManyBodySampled() with other forces and position constraints using the Les Miserables character interaction graph. Vertices repel each other using the Random Vertex Sampling algorithm; edges attract vertices, but the force is stronger for vertices within the same group; constraints confine vertices to rectangular regions based on the book volume that introduced each character; and each rectangular region has a gravitational force that draws the vertices of that region toward its center.