public MultiPhraseWeight(MultiPhraseQuery enclosingInstance, Searcher searcher)
			{
				InitBlock(enclosingInstance);
				this.similarity = Enclosing_Instance.GetSimilarity(searcher);
				
				// compute idf
			    int maxDoc = searcher.MaxDoc;
                foreach (Term[] terms in enclosingInstance.termArrays)
                {
                    foreach (Term term in terms)
                    {
                        idf += similarity.Idf(searcher.DocFreq(term), maxDoc);
                    }
                }
			}
 private void  InitBlock(MultiPhraseQuery enclosingInstance)
 {
     this.enclosingInstance = enclosingInstance;
 }
			private void  InitBlock(MultiPhraseQuery enclosingInstance)
			{
				this.enclosingInstance = enclosingInstance;
			}