code: func (h *SessionHandle) DropBindRecord(record *BindRecord) {
  	meta := &BindMeta{BindRecord: record}
  	meta.Status = deleted
  	hash := parser.DigestHash(record.OriginalSQL)
  	h.ch.removeDeletedBindMeta(hash, meta)
  	h.appendBindMeta(hash, meta)
  }
docs: // DropBindRecord drops a BindRecord in the cache.