diff --git a/pyinfra/server/bufferizer/lazy_bufferizer.py b/pyinfra/server/bufferizer/lazy_bufferizer.py
index e8e3937..ad40312 100644
--- a/pyinfra/server/bufferizer/lazy_bufferizer.py
+++ b/pyinfra/server/bufferizer/lazy_bufferizer.py
@@ -1,6 +1,7 @@
 import logging
 from collections import deque
 from itertools import chain, takewhile
+from typing import Iterable
 
 from funcy import first, repeatedly, flatten
 
@@ -48,7 +49,7 @@ class StreamBuffer:
         self.fn = bufferize(fn, buffer_size=buffer_size, null_value=[])
         self.result_stream = chain([])
 
-    def __call__(self, item):
+    def __call__(self, item) -> Iterable:
         self.push(item)
         yield from takewhile(is_not_nothing, repeatedly(self.pop))
 
diff --git a/pyinfra/server/server.py b/pyinfra/server/server.py
index 0bfb1ad..18ba11a 100644
--- a/pyinfra/server/server.py
+++ b/pyinfra/server/server.py
@@ -27,16 +27,16 @@ def make_streamable_and_wrap_in_packing_logic(fn, batched):
 
 class LazyProcessor:
     """Accepts computation requests (push) and lazily produces results (pop)."""
-    def __init__(self, stream_buffer: FlatStreamBuffer):
+    def __init__(self, flat_stream_buffer: FlatStreamBuffer):
         self.queue = Queue()
-        self.stream_buffer = stream_buffer
+        self.flat_stream_buffer = flat_stream_buffer
 
     def push(self, item):
         self.queue.append(item)
 
     def pop(self):
         items = stream_queue(self.queue)
-        return first(self.stream_buffer(items))
+        return first(self.flat_stream_buffer(items))
 
 
 class LazyRestProcessor:
@@ -73,7 +73,7 @@ def valid(result):
 
 def set_up_processing_server(package_processor):
     app = Flask(__name__)
-    stream = LazyRestProcessor(package_processor, submit_suffix="submit", pickup_suffix="pickup")
+    processor = LazyRestProcessor(package_processor, submit_suffix="submit", pickup_suffix="pickup")
 
     @app.route("/ready", methods=["GET"])
     def ready():
@@ -83,10 +83,10 @@ def set_up_processing_server(package_processor):
 
     @app.route("/submit", methods=["POST", "PATCH"])
     def submit():
-        return stream.push(request)
+        return processor.push(request)
 
     @app.route("/pickup", methods=["GET"])
     def pickup():
-        return stream.pop()
+        return processor.pop()
 
     return app
diff --git a/test/fixtures/server.py b/test/fixtures/server.py
index 2307d6d..393e653 100644
--- a/test/fixtures/server.py
+++ b/test/fixtures/server.py
@@ -38,8 +38,8 @@ def url(host, port):
 
 @pytest.fixture
 def server(processor_fn, buffer_size):
-    buffered_consumer = FlatStreamBuffer(processor_fn, buffer_size=buffer_size)
-    lazy_processor = LazyProcessor(buffered_consumer)
+    flat_stream_buffer = FlatStreamBuffer(processor_fn, buffer_size=buffer_size)
+    lazy_processor = LazyProcessor(flat_stream_buffer)
     return set_up_processing_server(lazy_processor)
 
 
@@ -54,7 +54,7 @@ def operation_conditionally_batched(operation, batched):
 
 
 @pytest.fixture
-def operation(item_type, batched, one_to_many):
+def operation(item_type, one_to_many):
     def upper(string: bytes, metadata):
         return string.decode().upper().encode(), metadata