def testTreeFilter(tree=None):
"""
:param tree: Sample tree string in bracket notation.
"""
if tree:
t = Tree(tree)
else:
t = Tree(
'((S(NP-SBJ (PRP They))(ADVP-TMP (RB never))(VP (VBD considered)(S (NP-SBJ (PRP themselves) (VP (TO to) (VP (VB be) (NP-PRD (NN anything) (RB else)))))))))')
t2 = t.copy(deep=True)
filterLexical(t2)
from nltk.draw.tree import draw_trees
draw_trees(t, t2)
