RuleModel m = new RuleModel();
m.name = "test expressionsString1";
FactPattern p = new FactPattern( "Person" );
SingleFieldConstraintEBLeftSide con = new SingleFieldConstraintEBLeftSide();
con.getExpressionLeftSide().appendPart( new ExpressionText( "field1" ) );
con.setOperator( "==" );
con.setValue( "goo" );
con.setConstraintValueType( SingleFieldConstraint.TYPE_LITERAL );
p.addConstraint( con );