diff --git a/.travis.yml b/.travis.yml
index 518b106..6474a58 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,11 @@
 dist: bionic
 sudo: false
 language: python
-python: 3.9
+python:
+  - 3.9
+  - 3.8
+  - 3.7
+  - 3.6
 cache:
   directories:
   - "$HOME/.cache/pip"
diff --git a/prototorch/models/__init__.py b/prototorch/models/__init__.py
index 728c922..466b2da 100644
--- a/prototorch/models/__init__.py
+++ b/prototorch/models/__init__.py
@@ -1,7 +1,5 @@
 """`models` plugin for the `prototorch` package."""
 
-from importlib.metadata import PackageNotFoundError, version
-
 from .callbacks import PrototypeConvergence, PruneLoserPrototypes
 from .cbc import CBC, ImageCBC
 from .glvq import (
diff --git a/prototorch/models/abstract.py b/prototorch/models/abstract.py
index d08dbec..34e5b76 100644
--- a/prototorch/models/abstract.py
+++ b/prototorch/models/abstract.py
@@ -1,7 +1,5 @@
 """Abstract classes to be inherited by prototorch models."""
 
-from typing import Final, final
-
 import pytorch_lightning as pl
 import torch
 import torchmetrics
@@ -43,7 +41,6 @@ class ProtoTorchBolt(pl.LightningModule):
         else:
             return optimizer
 
-    @final
     def reconfigure_optimizers(self):
         self.trainer.accelerator.setup_optimizers(self.trainer)
 
@@ -175,7 +172,7 @@ class NonGradientMixin(ProtoTorchMixin):
     """Mixin for custom non-gradient optimization."""
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
-        self.automatic_optimization: Final = False
+        self.automatic_optimization = False
 
     def training_step(self, train_batch, batch_idx, optimizer_idx=None):
         raise NotImplementedError
@@ -183,7 +180,6 @@ class NonGradientMixin(ProtoTorchMixin):
 
 class ImagePrototypesMixin(ProtoTorchMixin):
     """Mixin for models with image prototypes."""
-    @final
     def on_train_batch_end(self, outputs, batch, batch_idx, dataloader_idx):
         """Constrain the components to the range [0, 1] by clamping after updates."""
         self.proto_layer.components.data.clamp_(0.0, 1.0)
diff --git a/prototorch/models/callbacks.py b/prototorch/models/callbacks.py
index ed3a141..095f41d 100644
--- a/prototorch/models/callbacks.py
+++ b/prototorch/models/callbacks.py
@@ -55,7 +55,7 @@ class PruneLoserPrototypes(pl.Callback):
                 distribution = dict(zip(labels.tolist(), counts.tolist()))
                 if self.verbose:
                     print(f"Re-adding pruned prototypes...")
-                    print(f"{distribution=}")
+                    print(f"distribution={distribution}")
                 pl_module.add_prototypes(
                     distribution=distribution,
                     components_initializer=self.prototypes_initializer)
diff --git a/prototorch/models/glvq.py b/prototorch/models/glvq.py
index 6834399..ce4e1d5 100644
--- a/prototorch/models/glvq.py
+++ b/prototorch/models/glvq.py
@@ -112,7 +112,8 @@ class SiameseGLVQ(GLVQ):
         proto_opt = self.optimizer(self.proto_layer.parameters(),
                                    lr=self.hparams.proto_lr)
         # Only add a backbone optimizer if backbone has trainable parameters
-        if (bb_params := list(self.backbone.parameters())):
+        bb_params = list(self.backbone.parameters())
+        if (bb_params):
             bb_opt = self.optimizer(bb_params, lr=self.hparams.bb_lr)
             optimizers = [proto_opt, bb_opt]
         else:
diff --git a/prototorch/models/lvq.py b/prototorch/models/lvq.py
index b06a8dc..f398f93 100644
--- a/prototorch/models/lvq.py
+++ b/prototorch/models/lvq.py
@@ -28,8 +28,8 @@ class LVQ1(NonGradientMixin, GLVQ):
             self.proto_layer.load_state_dict({"_components": updated_protos},
                                              strict=False)
 
-        print(f"{dis=}")
-        print(f"{y=}")
+        print(f"dis={dis}")
+        print(f"y={y}")
         # Logging
         self.log_acc(dis, y, tag="train_acc")
 
diff --git a/prototorch/models/vis.py b/prototorch/models/vis.py
index 4f6b696..0f39f1a 100644
--- a/prototorch/models/vis.py
+++ b/prototorch/models/vis.py
@@ -251,8 +251,6 @@ class VisImgComp(Vis2DAbstract):
                                    size=self.embedding_data,
                                    replace=False)
             data = self.x_train[ind]
-            # print(f"{data.shape=}")
-            # print(f"{self.y_train[ind].shape=}")
             tb.add_embedding(data.view(len(ind), -1),
                              label_img=data,
                              global_step=None,
diff --git a/setup.py b/setup.py
index 12f461d..dd34adc 100644
--- a/setup.py
+++ b/setup.py
@@ -63,7 +63,7 @@ setup(
     url=PROJECT_URL,
     download_url=DOWNLOAD_URL,
     license="MIT",
-    python_requires=">=3.9",
+    python_requires=">=3.6",
     install_requires=INSTALL_REQUIRES,
     extras_require={
         "dev": DEV,
@@ -80,6 +80,9 @@ setup(
         "License :: OSI Approved :: MIT License",
         "Natural Language :: English",
         "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.6",
         "Operating System :: OS Independent",
         "Topic :: Scientific/Engineering :: Artificial Intelligence",
         "Topic :: Software Development :: Libraries",
diff --git a/tests/test_examples.sh b/tests/test_examples.sh
index 68f105b..fbac343 100755
--- a/tests/test_examples.sh
+++ b/tests/test_examples.sh
@@ -1,11 +1,27 @@
 #! /bin/bash
 
+
+# Read Flags
+gpu=0
+while [ -n "$1" ]; do
+	case "$1" in
+	    --gpu) gpu=1;;
+	    -g) gpu=1;;
+        *) path=$1;;
+	esac
+	shift
+done
+
+python --version
+echo "Using GPU: " $gpu
+
+# Loop
 failed=0
 
-for example in $(find $1 -maxdepth 1 -name "*.py")
+for example in $(find $path -maxdepth 1 -name "*.py")
 do
     echo  -n "$x" $example '... '
-    export DISPLAY= && python $example --fast_dev_run 1 --gpus 0 &> run_log.txt
+    export DISPLAY= && python $example --fast_dev_run 1 --gpus $gpu &> run_log.txt
     if [[ $? -ne 0 ]]; then
         echo "FAILED!!"
         cat run_log.txt