public void setFieldValue(_Fields field, @org.apache.thrift.annotation.Nullable java.lang.Object value) {
    switch (field) {
    case IS_DELETE:
      if (value == null) {
        unsetIsDelete();
      } else {
        setIsDelete((java.lang.Boolean)value);
      }
      break;

    case COLUMN:
      if (value == null) {
        unsetColumn();
      } else {
        if (value instanceof byte[]) {
          setColumn((byte[])value);
        } else {
          setColumn((java.nio.ByteBuffer)value);
        }
      }
      break;

    case VALUE:
      if (value == null) {
        unsetValue();
      } else {
        if (value instanceof byte[]) {
          setValue((byte[])value);
        } else {
          setValue((java.nio.ByteBuffer)value);
        }
      }
      break;

    case WRITE_TO_WAL:
      if (value == null) {
        unsetWriteToWAL();
      } else {
        setWriteToWAL((java.lang.Boolean)value);
      }
      break;

    }
  }
Returns true if field writeToWAL is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift/generated/Mutation.java