_col_op_proto: extraction=['my_val'] c=my_val:int<-/employees@org.spark.DistributedLiteral:{my_key:string, my_val:int}
_col_op_proto: extraction=['my_key'] c=value:string<-/employees@org.spark.DistributedLiteral:{my_key:string, my_val:int}
_as_nodes: x=<class 'karps.column.DataFrame'>:/employees@org.spark.DistributedLiteral:{my_key:string, my_val:int}
_as_nodes: x=<class 'karps.column.DataFrame'>:/structured_transform_0@org.spark.StructuredTransform:{filter:bool, value:string}
_as_nodes: x=<class 'karps.column.DataFrame'>:/filter_1@org.spark.Filter:string