@Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result
        + ((sampleDimension == null) ? 0 : sampleDimension.hashCode());
    result = prime * result + sampleFraction;
    result = prime * result + sampleNum;
    return result;
  }
Given an arbitrary object, determine if it falls within this sample.
ql/src/java/org/apache/hadoop/hive/ql/metadata/Sample.java