enumerate_parsimony at a node.extract.enumerate_parsimony returns a matrix containing all the
possible regime allocations for the nodes of a given subtree.
"extract"(x, node = attr(x$allocations, "ntaxa") + 1, what = c("solutions", "number", "cost"), ...)enumerate_parsimony",
result of function enumerate_parsimony.enumerate_parsimony, plot.enumerate_parsimony