memo:
```bash
> ruby -e 's = 117' --parser=prism --dump=parsetree
@ ProgramNode (location: (1,0)-(1,7))
+-- locals: [:s]
+-- statements:
    @ StatementsNode (location: (1,0)-(1,7))
    +-- body: (length: 1)
        +-- @ LocalVariableWriteNode (location: (1,0)-(1,7))
            +-- name: :s
            +-- depth: 0
            +-- name_loc: (1,0)-(1,1) = "s"
            +-- value:
            |   @ IntegerNode (location: (1,4)-(1,7))
            |   +-- IntegerBaseFlags: decimal
            |   +-- value: 117
            +-- operator_loc: (1,2)-(1,3) = "="
```