class_docstr: Instead of marching the sub-matchers along in parallel, this matcher
  pre-reads the scores for a large block of documents at a time from each
  matcher, accumulating the scores in an array.
  
  This is faster than the implementation using a binary tree of
  :class:`~whoosh.matching.binary.UnionMatcher` objects (possibly just
  because of less overhead), but it doesn't allow getting information about
  the "current" document other than the score, because there isn't really a
  current document, just an array of scores.
code: def skip_to_quality(self, minquality):
      skipped = 0
      while self.is_active() and self.block_quality() <= minquality:
          skipped += 1
          self._docnum = self._limit
          self._read_part()
      if self.is_active():
          self._find_next()
      return skipped
  
imports: from __future__ import division
  from array import array
  from whoosh.compat import xrange
  from whoosh.matching import mcore
label_desc: Use image node_id 11 for calling the ArrayUnionMatcher obj's underlying member method code with example usage: obj.skip_to_quality(minquality) and returns: skipped