code: def get_unused_primitives(specified, used):
      """Get a list of unused primitives based on a list of specified primitives and a list of output features"""
      if not specified:
          return []
      specified = {
          camel_and_title_to_snake(primitive)
          if isinstance(primitive, str)
          else primitive.name
          for primitive in specified
      }
      return sorted(specified.difference(used))
  
imports: from featuretools.feature_base import AggregationFeature, FeatureOutputSlice, GroupByTransformFeature, TransformFeature
  from featuretools.utils.gen_utils import camel_and_title_to_snake
label_desc: Use image node_id 2 for calling a global function with example usage: get_unused_primitives(specified, used) and returns: sorted, list