public boolean equals(TCellVisibility that) {
    if (that == null)
      return false;
    if (this == that)
      return true;

    boolean this_present_expression = true && this.isSetExpression();
    boolean that_present_expression = true && that.isSetExpression();
    if (this_present_expression || that_present_expression) {
      if (!(this_present_expression && that_present_expression))
        return false;
      if (!this.expression.equals(that.expression))
        return false;
    }

    return true;
  }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/TCellVisibility.java