prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  Misleading Error "Please install necessary libs for CatBoostModel."
  ## 🐛 Bug Description
  
  Qlib does not require the installation of packages like `CatBoostModel`
  
  But the output looks a little misleading.
  
  
  ## To Reproduce
  Run `examples/workflow_by_code.ipynb` in jupyter notebook.
  
  ## Expected Behavior
  
  Successfully run the script without installing CatBoostModel and warning.
  
  ## Screenshot
  ![image](https://user-images.githubusercontent.com/465606/177905185-57a43596-b180-4c52-8df9-0e88b95640b4.png)
  
  <!-- A screenshot of the error message or anything shouldn't appear-->
  
  
  </issue>
  <code>
  [start of qlib/contrib/model/__init__.py]
  1 # Copyright (c) Microsoft Corporation.
  2 # Licensed under the MIT License.
  3 try:
  4     from .catboost_model import CatBoostModel
  5 except ModuleNotFoundError:
  6     CatBoostModel = None
  7     print("Please install necessary libs for CatBoostModel.")
  8 try:
  9     from .double_ensemble import DEnsembleModel
  10     from .gbdt import LGBModel
  11 except ModuleNotFoundError:
  12     DEnsembleModel, LGBModel = None, None
  13     print(
  14         "ModuleNotFoundError. DEnsembleModel and LGBModel are skipped. (optional: maybe installing lightgbm can fix it.)"
  15     )
  16 try:
  17     from .xgboost import XGBModel
  18 except ModuleNotFoundError:
  19     XGBModel = None
  20     print("ModuleNotFoundError. XGBModel is skipped(optional: maybe installing xgboost can fix it).")
  21 try:
  22     from .linear import LinearModel
  23 except ModuleNotFoundError:
  24     LinearModel = None
  25     print("ModuleNotFoundError. LinearModel is skipped(optional: maybe installing scipy and sklearn can fix it).")
  26 # import pytorch models
  27 try:
  28     from .pytorch_alstm import ALSTM
  29     from .pytorch_gats import GATs
  30     from .pytorch_gru import GRU
  31     from .pytorch_lstm import LSTM
  32     from .pytorch_nn import DNNModelPytorch
  33     from .pytorch_tabnet import TabnetModel
  34     from .pytorch_sfm import SFM_Model
  35     from .pytorch_tcn import TCN
  36     from .pytorch_add import ADD
  37 
  38     pytorch_classes = (ALSTM, GATs, GRU, LSTM, DNNModelPytorch, TabnetModel, SFM_Model, TCN, ADD)
  39 except ModuleNotFoundError:
  40     pytorch_classes = ()
  41     print("ModuleNotFoundError.  PyTorch models are skipped (optional: maybe installing pytorch can fix it).")
  42 
  43 all_model_classes = (CatBoostModel, DEnsembleModel, LGBModel, XGBModel, LinearModel) + pytorch_classes
  44
  [end of qlib/contrib/model/__init__.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/qlib/contrib/model/__init__.py b/qlib/contrib/model/__init__.py
  --- a/qlib/contrib/model/__init__.py
  +++ b/qlib/contrib/model/__init__.py
  @@ -4,7 +4,7 @@
       from .catboost_model import CatBoostModel
   except ModuleNotFoundError:
       CatBoostModel = None
  -    print("Please install necessary libs for CatBoostModel.")
  +    print("ModuleNotFoundError. CatBoostModel are skipped. (optional: maybe installing CatBoostModel can fix it.)")
   try:
       from .double_ensemble import DEnsembleModel
       from .gbdt import LGBModel
  
verification_info: {"golden_diff": "diff --git a/qlib/contrib/model/__init__.py b/qlib/contrib/model/__init__.py\n--- a/qlib/contrib/model/__init__.py\n+++ b/qlib/contrib/model/__init__.py\n@@ -4,7 +4,7 @@\n     from .catboost_model import CatBoostModel\n except ModuleNotFoundError:\n     CatBoostModel = None\n-    print(\"Please install necessary libs for CatBoostModel.\")\n+    print(\"ModuleNotFoundError. CatBoostModel are skipped. (optional: maybe installing CatBoostModel can fix it.)\")\n try:\n     from .double_ensemble import DEnsembleModel\n     from .gbdt import LGBModel\n", "issue": "Misleading Error \"Please install necessary libs for CatBoostModel.\"\n## \ud83d\udc1b Bug Description\r\n\r\nQlib does not require the installation of packages like `CatBoostModel`\r\n\r\nBut the output looks a little misleading.\r\n\r\n\r\n## To Reproduce\r\nRun `examples/workflow_by_code.ipynb` in jupyter notebook.\r\n\r\n## Expected Behavior\r\n\r\nSuccessfully run the script without installing CatBoostModel and warning.\r\n\r\n## Screenshot\r\n![image](https://user-images.githubusercontent.com/465606/177905185-57a43596-b180-4c52-8df9-0e88b95640b4.png)\r\n\r\n<!-- A screenshot of the error message or anything shouldn't appear-->\r\n\n", "before_files": [{"content": "# Copyright (c) Microsoft Corporation.\n# Licensed under the MIT License.\ntry:\n    from .catboost_model import CatBoostModel\nexcept ModuleNotFoundError:\n    CatBoostModel = None\n    print(\"Please install necessary libs for CatBoostModel.\")\ntry:\n    from .double_ensemble import DEnsembleModel\n    from .gbdt import LGBModel\nexcept ModuleNotFoundError:\n    DEnsembleModel, LGBModel = None, None\n    print(\n        \"ModuleNotFoundError. DEnsembleModel and LGBModel are skipped. (optional: maybe installing lightgbm can fix it.)\"\n    )\ntry:\n    from .xgboost import XGBModel\nexcept ModuleNotFoundError:\n    XGBModel = None\n    print(\"ModuleNotFoundError. XGBModel is skipped(optional: maybe installing xgboost can fix it).\")\ntry:\n    from .linear import LinearModel\nexcept ModuleNotFoundError:\n    LinearModel = None\n    print(\"ModuleNotFoundError. LinearModel is skipped(optional: maybe installing scipy and sklearn can fix it).\")\n# import pytorch models\ntry:\n    from .pytorch_alstm import ALSTM\n    from .pytorch_gats import GATs\n    from .pytorch_gru import GRU\n    from .pytorch_lstm import LSTM\n    from .pytorch_nn import DNNModelPytorch\n    from .pytorch_tabnet import TabnetModel\n    from .pytorch_sfm import SFM_Model\n    from .pytorch_tcn import TCN\n    from .pytorch_add import ADD\n\n    pytorch_classes = (ALSTM, GATs, GRU, LSTM, DNNModelPytorch, TabnetModel, SFM_Model, TCN, ADD)\nexcept ModuleNotFoundError:\n    pytorch_classes = ()\n    print(\"ModuleNotFoundError.  PyTorch models are skipped (optional: maybe installing pytorch can fix it).\")\n\nall_model_classes = (CatBoostModel, DEnsembleModel, LGBModel, XGBModel, LinearModel) + pytorch_classes\n", "path": "qlib/contrib/model/__init__.py"}]}