def addNewCluster(self, tf, sentence):
"""
Creates a new cluster and adds it to the clusters.
tf - term frequency counts of the given sentence
sentence - sentence to be added to the cluster
"""
self.newCID += 1
newCluster = Cluster(self.newCID)
newCluster.tf = tf
newCluster.addSentenceToCluster(sentence)
self.clusters[self.newCID] = newCluster
print "Added new cluster for cid: {}".format(self.newCID)
