AlterQuery  test (children 3)
 ExpressionList (children 1)
  AlterCommand UPDATE (children 2)
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier json.a
     Literal UInt64_42
   ExpressionList (children 1)
    Assignment s (children 1)
     Literal \'{}\'
 Identifier test
 Set
