This line
https://github.com/lmaurits/BEASTling/blob/ba264911ff591dbd3487a519c5faa24ec623fa3d/beastling/treepriors/base.py#L42
is the only one in TreePrior.add_state_nodes that makes use of the argument beastxml, instead of its beastxml.state attribute, and for a frivolous purpose. We should make the tree prior generally aware of tip calibrations (so eg. the Yule Prior can insist that there be none), and then make add_state_nodes only aware of the state to put its own state nodes into.
This line https://github.com/lmaurits/BEASTling/blob/ba264911ff591dbd3487a519c5faa24ec623fa3d/beastling/treepriors/base.py#L42 is the only one in
TreePrior.add_state_nodesthat makes use of the argumentbeastxml, instead of itsbeastxml.stateattribute, and for a frivolous purpose. We should make the tree prior generally aware of tip calibrations (so eg. the Yule Prior can insist that there be none), and then makeadd_state_nodesonly aware of thestateto put its own state nodes into.