Add stream clone method

holoviews/core/decollate.py

@@ -140,7 +140,7 @@ def to_expr_extract_streams(
             else:
                 # Add new stream
                 stream_index = StreamIndex(index=len(streams))
-                cloned_stream = type(hvobj)(**hvobj.contents)
+                cloned_stream = hvobj.clone()
                 original_streams.append(hvobj)
                 streams.append(cloned_stream)
                 if container_key is not None:

holoviews/streams.py

@@ -264,6 +264,9 @@ def __init__(self, rename={}, source=None, subscribers=[], linked=False,
             else:
                 self.registry[source] = [self]
 
+    def clone(self):
+        """Return new stream with identical properties and no subscribers"""
+        return type(self)(**self.contents)
 
     @property
     def subscribers(self):
@@ -870,6 +873,9 @@ def __init__(self, input_stream, **params):
         # added to our values list
         self.input_stream.event()
 
+    def clone(self):
+        return type(self)(self.input_stream.clone(), **self.contents)
+
     def clear_history(self):
         del self.values[:]
         self.event()
@@ -921,6 +927,9 @@ def __init__(self, source, **params):
             source=source, input_streams=input_streams, exclusive=True, **params
         )
 
+    def clone(self):
+        return type(self)(self.source, **self.contents)
+
     def _build_selection_streams(self, source):
         from holoviews.core.spaces import DynamicMap
         if isinstance(source, DynamicMap):