Takes a collection object (or a filepath to collection object), returns
    True if it includes a decision to include the specified tree

def tree_is_in_collection(collection, study_id=None, tree_id=None):
    """Takes a collection object (or a filepath to collection object), returns
    True if it includes a decision to include the specified tree
    """
    included = collection_to_included_trees(collection)
    study_id = study_id.strip()
    tree_id = tree_id.strip()
    for decision in included:
        if decision['studyID'] == study_id and decision['treeID'] == tree_id:
            return True
    return False