DSL EXPRESSION:
true {@x=1;@y=2}

AST:
"block" [tt:block] [nt:StatementBlock]
    "true" [tt:literal_true] [nt:CondBlock]
        "true" [tt:literal_true] [nt:bool_literal]
        "block" [tt:block] [nt:StatementBlockInBraces]
            "block" [tt:block] [nt:StatementBlock]
                "=" [tt:equals] [nt:Assignment]
                    "@x" [tt:oosvar_name] [nt:DirectOosvarValue]
                    "1" [tt:int_literal] [nt:int_literal]
                "=" [tt:equals] [nt:Assignment]
                    "@y" [tt:oosvar_name] [nt:DirectOosvarValue]
                    "2" [tt:int_literal] [nt:int_literal]

