Refactor child pad removed default error message

lib/membrane/core/callback_handler.ex

@@ -141,7 +141,12 @@ defmodule Membrane.Core.CallbackHandler do
         e in UndefinedFunctionError ->
           with %{module: ^module, function: ^callback, arity: arity} <- e do
             reraise CallbackError,
-                    [kind: :not_implemented, callback: {module, callback}, arity: arity],
+                    [
+                      kind: :not_implemented,
+                      callback: {module, callback},
+                      arity: arity,
+                      args: args
+                    ],
                     __STACKTRACE__
           end
 

lib/membrane/exceptions.ex

@@ -59,6 +59,28 @@ defmodule Membrane.CallbackError do
     %__MODULE__{message: msg}
   end
 
+  defp mk_exception(:not_implemented, {module, :handle_child_pad_removed}, opts) do
+    [child, pad, _context, _custom_state] = Keyword.fetch!(opts, :args)
+
+    component_type_string =
+      cond do
+        Membrane.Pipeline.pipeline?(module) -> "Pipeline"
+        Membrane.Bin.bin?(module) -> "Bin"
+      end
+
+    callback_ref = "`c:Membrane.#{component_type_string}.handle_child_pad_removed/4`"
+
+    msg = """
+    Bin #{inspect(child)} removed its pad #{inspect(pad)}, but callback #{callback_ref} is not implemented in #{inspect(module)}.
+
+    This means, that `#{inspect(child)} removed the pad on its own, without knowledge of its parent. For example it could happen due to removing #{inspect(child)}'s child linked to the #{inspect(child)}'s inner pad or by removing link between #{inspect(child)} and its child.
+
+    If you want to handle this scenario, implement #{callback_ref} callback in #{inspect(module)}.
+    """
+
+    %__MODULE__{message: msg}
+  end
+
   defp mk_exception(:not_implemented, {module, fun}, opts) do
     arity = Keyword.fetch!(opts, :arity)