public static boolean execute(ExecutablePool pool, String region, Object key, MODE mode) {
    AbstractOp op = new ContainsKeyOpImpl(region, key, mode);
    Boolean result = (Boolean) pool.execute(op);
    return result;
  }
Does a region entry containsKey on a server using connections from the given pool to
communicate with the server.

@param pool the pool to use to communicate with the server.
@param region the name of the region to do the entry containsKey on
@param key the entry key to do the containsKey on
@return the result of invoking containsKey on the server
geode-core/src/main/java/org/apache/geode/cache/client/internal/ContainsKeyOp.java