old_contents: # pylint: disable=useless-import-alias
  """
  Declarative API for downloading sources required by benchbuild.
  """
  from .base import FetchableSource as FetchableSource
  from .base import Variant as Variant
  from .base import VariantContext as VariantContext
  from .base import context as context
  from .base import default as default
  from .base import nosource as nosource
  from .base import primary as primary
  from .base import product as product
  from .base import sources_as_dict as sources_as_dict
  from .base import to_str as to_str
  from .git import Git as Git
  from .git import GitSubmodule as GitSubmodule
  from .http import HTTP as HTTP
  from .versions import BaseVersionFilter as BaseVersionFilter
  from .versions import BaseVersionGroup as BaseVersionGroup
  from .versions import SingleVersionFilter as SingleVersionFilter
  
new_contents: # pylint: disable=useless-import-alias
  """
  Declarative API for downloading sources required by benchbuild.
  """
  from .base import FetchableSource as FetchableSource
  from .base import Expandable as Expandable
  from .base import ContextAwareSource as ContextAwareSource
  from .base import ContextEnumeratorFn as ContextEnumeratorFn
  from .base import ExpandableAndFetchableSource as ExpandableAndFetchableSource
  from .base import Variant as Variant
  from .base import VariantContext as VariantContext
  from .base import context as context
  from .base import default as default
  from .base import nosource as nosource
  from .base import primary as primary
  from .base import product as product
  from .base import enumerate as enumerate
  from .base import sources_as_dict as sources_as_dict
  from .base import to_str as to_str
  from .git import Git as Git
  from .git import GitSubmodule as GitSubmodule
  from .http import HTTP as HTTP
  from .versions import BaseVersionFilter as BaseVersionFilter
  from .versions import BaseVersionGroup as BaseVersionGroup
  from .versions import SingleVersionFilter as SingleVersionFilter
  
subject: expand public source API