Add an Observable specific overload first with docstring to make pyli…

…nt happy.

rx/core/observable/observable.py

@@ -216,7 +216,25 @@ def set_disposable(_: abc.Scheduler = None, __: Any = None):
         return Disposable(auto_detach_observer.dispose)
 
     @overload
-    def pipe(self) -> 'Observable':  # pylint: disable=no-self-use
+    def pipe(self, *operators: Callable[['Observable'], 'Observable']) -> 'Observable':  # pylint: disable=no-self-use
+        """Compose multiple operators left to right.
+
+        Composes zero or more operators into a functional composition.
+        The operators are composed to right. A composition of zero
+        operators gives back the original source.
+
+        source.pipe() == source
+        source.pipe(f) == f(source)
+        source.pipe(g, f) == f(g(source))
+        source.pipe(h, g, f) == f(g(h(source)))
+        ...
+
+        Returns the composed observable.
+        """
+        ...
+
+    @overload
+    def pipe(self) -> 'Observable':  # pylint: disable=function-redefined, no-self-use
         ...  # pylint: disable=pointless-statement
 
     @overload
@@ -264,7 +282,7 @@ def pipe(self,  # pylint: disable=function-redefined, no-self-use, too-many-argu
         ...  # pylint: disable=pointless-statement
 
     @overload
-    def pipe(self,  # pylint: disable=function-redefined,too-many-arguments,no-self-use
+    def pipe(self,  # pylint: disable=function-redefined, no-self-use, too-many-arguments
              op1: Callable[['Observable'], A],
              op2: Callable[[A], B],
              op3: Callable[[B], C],
@@ -275,7 +293,7 @@ def pipe(self,  # pylint: disable=function-redefined,too-many-arguments,no-self-
         ...  # pylint: disable=pointless-statement
 
     # pylint: disable=function-redefined
-    def pipe(self, *operators: Callable[['Observable'], Any]) -> Any:  # type: ignore
+    def pipe(self, *operators: Callable[['Observable'], Any]) -> Any:
         """Compose multiple operators left to right.
 
         Composes zero or more operators into a functional composition.

rx/core/pipe.py

@@ -11,7 +11,27 @@
 
 
 @overload
-def pipe() -> Callable[[A], A]:
+def pipe(*operators: Callable[['Observable'], 'Observable']) -> Callable[['Observable'], 'Observable']:  # type: ignore
+    """Compose multiple operators left to right.
+
+    Composes zero or more operators into a functional composition. The
+    operators are composed to left to right. A composition of zero
+    operators gives back the source.
+
+    Examples:
+        >>> pipe()(source) == source
+        >>> pipe(f)(source) == f(source)
+        >>> pipe(f, g)(source) == g(f(source))
+        >>> pipe(f, g, h)(source) == h(g(f(source)))
+        ...
+
+    Returns:
+        The composed observable.
+    """
+    ...
+
+@overload
+def pipe() -> Callable[[A], A]:  # pylint: disable=function-redefined
     ...  # pylint: disable=pointless-statement
 
 
@@ -64,7 +84,7 @@ def pipe(op1: Callable[[A], B],  # pylint: disable=function-redefined,too-many-a
 
 
 # pylint: disable=function-redefined
-def pipe(*operators: Callable[[Any], Any]) -> Callable[[Any], Any]:  # type: ignore
+def pipe(*operators: Callable[[Any], Any]) -> Callable[[Any], Any]:
     """Compose multiple operators left to right.
 
     Composes zero or more operators into a functional composition. The