code: protected void checkParametersValidity2(CreateFrameExecutor cfe) {
      long byteEstimate = cfe.estimatedByteSize();
      long clusterFreeMem = H2O.CLOUD.free_mem();
      double gb = (double) (1 << 30);
      check(byteEstimate <= clusterFreeMem,
          String.format("Frame is expected to require %.3fGb, which will not fit into H2O's free memory of %.3fGb",
              byteEstimate/gb, clusterFreeMem/gb));
    }
docs: Final step of parameter testing, after the {@link CreateFrameExecutor}
  has been set up, but just before the actual frame creation commences.
  This method shall only be used to perform checks that cannot be done
  without the {@link CreateFrameExecutor} instance.