From b1a9776943293d1f835a7eef4ad73e13633f2ca3 Mon Sep 17 00:00:00 2001
From: Philipp Rudiger <P.Rudiger@ed.ac.uk>
Date: Thu, 21 Dec 2017 13:04:01 +0000
Subject: [PATCH] Cleaned up top-level namespace

---
 holoviews/__init__.py         | 10 ++++------
 holoviews/core/element.py     |  6 ++++++
 holoviews/core/ndmapping.py   |  2 +-
 holoviews/element/__init__.py |  2 +-
 tests/core/testoptions.py     |  6 ++++--
 5 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/holoviews/__init__.py b/holoviews/__init__.py
index 55da68cf2d..3ab691950d 100644
--- a/holoviews/__init__.py
+++ b/holoviews/__init__.py
@@ -17,13 +17,11 @@
 
 from .core import archive, config                        # noqa (API import)
 from .core.dimension import OrderedDict, Dimension       # noqa (API import)
-from .core.boundingregion import BoundingBox             # noqa (API import)
 from .core.options import (Options, Store, Cycle,        # noqa (API import)
-                           Palette, StoreOptions)
-from .core.layout import *                               # noqa (API import)
-from .core.element import *                              # noqa (API import)
-from .core.overlay import *                              # noqa (API import)
-from .core.tree import *                                 # noqa (API import)
+                           Palette)
+from .core.layout import Layout, NdLayout, AdjointLayout # noqa (API import)
+from .core.element import Collator                       # noqa (API import)
+from .core.overlay import Overlay, NdOverlay             # noqa (API import)
 from .core.spaces import (HoloMap, Callable, DynamicMap, # noqa (API import)
                           GridSpace, GridMatrix)
 
diff --git a/holoviews/core/element.py b/holoviews/core/element.py
index ee6a68376f..7c702d1da5 100644
--- a/holoviews/core/element.py
+++ b/holoviews/core/element.py
@@ -22,6 +22,8 @@ class Element(ViewableElement, Composable, Overlayable):
 
     group = param.String(default='Element', constant=True)
 
+    __abstract = True
+
     def hist(self, dimension=None, num_bins=20, bin_range=None,
              adjoin=True, individually=True, **kwargs):
         """
@@ -262,6 +264,8 @@ class Element2D(Element):
               of the Element in 2D space defined as four-tuple
               defining the (left, bottom, right and top) edges.""")
 
+    __abstract = True
+
 
 class Element3D(Element2D):
 
@@ -271,6 +275,8 @@ class Element3D(Element2D):
                in 3D space defined as (xmin, ymin, zmin,
                xmax, ymax, zmax).""")
 
+    __abstract = True
+
 
 class Collator(NdMapping):
     """
diff --git a/holoviews/core/ndmapping.py b/holoviews/core/ndmapping.py
index fa59fb2fed..4b5236714c 100644
--- a/holoviews/core/ndmapping.py
+++ b/holoviews/core/ndmapping.py
@@ -719,7 +719,7 @@ class UniformNdMapping(NdMapping):
 
     data_type = (ViewableElement, NdMapping)
 
-    _abstract = True
+    __abstract = True
     _deep_indexable = True
     _auxiliary_component = False
 
diff --git a/holoviews/element/__init__.py b/holoviews/element/__init__.py
index 27fb2783eb..d1772b7515 100644
--- a/holoviews/element/__init__.py
+++ b/holoviews/element/__init__.py
@@ -91,7 +91,7 @@ def vectorfield(self, kdims=None, vdims=None, groupby=None, **kwargs):
 
 
 def public(obj):
-    if not isinstance(obj, type) or getattr(obj, 'abstract', False):
+    if not isinstance(obj, type) or getattr(obj, 'abstract', False) and not obj is Element:
         return False
     return issubclass(obj, Element)
 
diff --git a/tests/core/testoptions.py b/tests/core/testoptions.py
index 71e1908d33..9b5a90c01c 100644
--- a/tests/core/testoptions.py
+++ b/tests/core/testoptions.py
@@ -1,8 +1,10 @@
 import os
 import pickle
 import numpy as np
-from holoviews import Store, StoreOptions, Histogram, Image
-from holoviews.core.options import OptionError, Cycle, Options, OptionTree, options_policy
+from holoviews import Store, Histogram, Image
+from holoviews.core.options import (
+    OptionError, Cycle, Options, OptionTree, StoreOptions, options_policy
+)
 from holoviews.element.comparison import ComparisonTestCase
 from holoviews import plotting              # noqa Register backends
 from unittest import SkipTest