code: def is_collection(item):
      
      return not isinstance(item, six.string_types) and isinstance(item, (collections.Set, collections.Sequence))
docs: Returns True if the item is a collection class: list, tuple, set, frozenset
      or any other class that resembles one of these (using abstract base classes).
  
      >>> is_collection(0)
      False
      >>> is_collection(0.1)
      False
      >>> is_collection('')
      False
      >>> is_collection({})
      False
      >>> is_collection({}.keys())
      True
      >>> is_collection([])
      True
      >>> is_collection(())
      True
      >>> is_collection(set())
      True
      >>> is_collection(frozenset())
      True
      >>> from coaster.utils import InspectableSet
      >>> is_collection(InspectableSet({1, 2}))
      True