public void read(org.apache.thrift.protocol.TProtocol iprot, getTableNamesByPattern_args struct) throws org.apache.thrift.TException {
        org.apache.thrift.protocol.TField schemeField;
        iprot.readStructBegin();
        while (true)
        {
          schemeField = iprot.readFieldBegin();
          if (schemeField.type == org.apache.thrift.protocol.TType.STOP) { 
            break;
          }
          switch (schemeField.id) {
            case 1: // REGEX
              if (schemeField.type == org.apache.thrift.protocol.TType.STRING) {
                struct.regex = iprot.readString();
                struct.setRegexIsSet(true);
              } else { 
                org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
              }
              break;
            case 2: // INCLUDE_SYS_TABLES
              if (schemeField.type == org.apache.thrift.protocol.TType.BOOL) {
                struct.includeSysTables = iprot.readBool();
                struct.setIncludeSysTablesIsSet(true);
              } else { 
                org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
              }
              break;
            default:
              org.apache.thrift.protocol.TProtocolUtil.skip(iprot, schemeField.type);
          }
          iprot.readFieldEnd();
        }
        iprot.readStructEnd();

        // check for required fields of primitive type, which can't be checked in the validate method
        if (!struct.isSetIncludeSysTables()) {
          throw new org.apache.thrift.protocol.TProtocolException("Required field 'includeSysTables' was not found in serialized data! Struct: " + toString());
        }
        struct.validate();
      }
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/THBaseService.java