DSL EXPRESSION:
$i *= 2


AST:
* statement block
    * assignment "="
        * direct field value "i"
        * operator "*"
            * direct field value "i"
            * int literal "2"

a   b   i x                   y
pan pan 2 0.3467901443380824  0.7268028627434533
eks pan 4 0.7586799647899636  0.5221511083334797
wye wye 6 0.20460330576630303 0.33831852551664776
eks wye 8 0.38139939387114097 0.13418874328430463
