def find_terms(self, terms):
'''
Encontra a posicao do termo na lista de termos
@return int
'''
# trata o termo
terms = Document.prepare(terms)
# encontra a posicao para cada termo
positions = list()
for term in terms:
try:
positions.append(self.terms().index(term))
except:
positions.append(-1)
return positions
