code: func (tf tFiles) overlaps(icmp *iComparer, umin, umax []byte, unsorted bool) bool {
  	if unsorted {
  		// Check against all files.
  		for _, t := range tf {
  			if t.overlaps(icmp, umin, umax) {
  				return true
  			}
  		}
  		return false
  	}
  
  	i := 0
  	if len(umin) > 0 {
  		// Find the earliest possible internal key for min.
  		i = tf.searchMax(icmp, makeInternalKey(nil, umin, keyMaxSeq, keyTypeSeek))
  	}
  	if i >= len(tf) {
  		// Beginning of range is after all files, so no overlap.
  		return false
  	}
  	return !tf[i].before(icmp, umax)
  }
docs: // Returns true if given key range overlaps with one or more
  // tables key range. If unsorted is true then binary search will not be used.