for( int i = 0; i < projects.size(); i++ )
{
Pair<RexNode, String> exp = projects.get( i );
if( !( exp.left instanceof RexInputRef ) ) // RexCall or RexLiteral
builder.addExpr( exp.left );
int index = i;
if( exp.left instanceof RexInputRef )
index = ( (RexInputRef) exp.left ).getIndex();