re-use bsread.Source docstring for BSCache

bstrd/bscache.py

@@ -1,4 +1,4 @@
-from bsread import source, dispatcher
+from bsread import dispatcher, source, Source
 from bsread import BIND, CONNECT, PUSH, PULL, PUB, SUB # make these easier to access
 
 from .bsvar import BSVar
@@ -130,6 +130,14 @@ class BSCache:
 
 
 
+BSCache.__doc__ = f"""
+maxsize: Size of the queue between main and receiving thread.
+
+kwargs are forwarded to bsread.source:{Source.__init__.__doc__}
+"""
+
+
+
 def check_availability(name):
     if not is_available(name):
         raise ValueError(f"channel {name} is not available")