CreateQuery 00662_has_nullable (children 3)
 Identifier 00662_has_nullable
 Columns definition (children 1)
  ExpressionList (children 1)
   ColumnDeclaration a (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType UInt64
 Storage definition (children 1)
  Function Memory