Traverses the cell type hierarchy, summing up cell type fractions when necessary.
find_children(node, fractions, method_dataset = NULL)data.tree::Node corresponding to a controlled vocabulary cell type
a named list of fractions for each method_cell_type
character identifying the method or dataset in the celltype_mapping. If NULL, the input vector already uses controlled vocabulary.
numeric Either (1) the value of the method_cell_type mapped to cell_type, (2) the sum of all child nodes (recursively) of cell_type (3) NA, if the mapping cannot be resolved, i.e. at least one of the child nodes is missing.