public final UnresolvedReferenceExpression operand(int i) {
		String name = String.valueOf(i);
		if (getAggBufferNames().contains(name)) {
			throw new IllegalStateException(
				String.format("Agg buffer name(%s) should not same to operands.", name));
		}
		return new UnresolvedReferenceExpression(name);
	}
public final UnresolvedReferenceExpression operand ( int i ) { String name = String . valueOf ( i ) ; if ( getAggBufferNames ( ) . contains ( name ) ) { throw new IllegalStateException ( String . format ( "Agg buffer name(%s) should not same to operands." , name ) ) ; } return new UnresolvedReferenceExpression ( name ) ; }
Arg of accumulate and retract, the input value (usually obtained from a new arrived data).