2## This example shows how to construct a molecular hierarchy consisting of two proteins, and then apply connectivity restraint obtained from pulldown experimental data to these two proteins.
3##
4## On the following figure, we see an XML representation of the molecular hierarchy.
5##
6## \include eg1_representation.xml
7##
8## Each level of molecular hierarchy corresponds to an XML tag. Each tag can have
9## optional attributes. In this example, each protein has a unique id. Protein1 has
10## 2 chains. The first chain is constructed from the PDB file using
11## IMP::atom::CAlphaSelector. The second chain is represented by a sphere fragment
12## that is big enough to contain 10 residues. Protein2 is constructed using the