prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  ImportError: cannot import name 'marker_trait' from 'chaco.api'
  **Problem Description**
  ImportError: cannot import name 'marker_trait' from 'chaco.api' when trying to run a 2008 demo
  
  **Reproduction Steps:**
  
  ```python
  python chaco/examples/tutorials/scipy2008/traits_example.py
  ```
  
  **Expected behavior:**
  test past
  
  **OS, Python version:** [MacOS, python3.8 (with or without edm) or 3.11]
  
  
  </issue>
  <code>
  [start of examples/tutorials/scipy2008/traits_example.py]
  1 from numpy import linspace, sin
  2 
  3 from enable.api import ColorTrait
  4 from chaco.api import ArrayPlotData, Plot, marker_trait
  5 from enable.api import ComponentEditor
  6 from traits.api import HasTraits, Instance, Int
  7 from traitsui.api import Group, Item, View
  8 
  9 
  10 class ScatterPlotTraits(HasTraits):
  11 
  12     plot = Instance(Plot)
  13     color = ColorTrait("blue")
  14     marker = marker_trait
  15     marker_size = Int(4)
  16 
  17     traits_view = View(
  18         Group(
  19             Item("color", label="Color", style="custom"),
  20             Item("marker", label="Marker"),
  21             Item("marker_size", label="Size"),
  22             Item("plot", editor=ComponentEditor(), show_label=False),
  23             orientation="vertical",
  24         ),
  25         width=800,
  26         height=600,
  27         resizable=True,
  28         title="Chaco Plot",
  29     )
  30 
  31     def __init__(self):
  32         # Create the data and the PlotData object
  33         x = linspace(-14, 14, 100)
  34         y = sin(x) * x ** 3
  35         plotdata = ArrayPlotData(x=x, y=y)
  36         # Create a Plot and associate it with the PlotData
  37         plot = Plot(plotdata)
  38         # Create a line plot in the Plot
  39         self.renderer = plot.plot(("x", "y"), type="scatter", color="blue")[0]
  40         self.plot = plot
  41 
  42     def _color_changed(self):
  43         self.renderer.color = self.color
  44 
  45     def _marker_changed(self):
  46         self.renderer.marker = self.marker
  47 
  48     def _marker_size_changed(self):
  49         self.renderer.marker_size = self.marker_size
  50 
  51 
  52 # ===============================================================================
  53 # demo object that is used by the demo.py application.
  54 # ===============================================================================
  55 demo = ScatterPlotTraits()
  56 
  57 if __name__ == "__main__":
  58     demo.configure_traits()
  59
  [end of examples/tutorials/scipy2008/traits_example.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/examples/tutorials/scipy2008/traits_example.py b/examples/tutorials/scipy2008/traits_example.py
  --- a/examples/tutorials/scipy2008/traits_example.py
  +++ b/examples/tutorials/scipy2008/traits_example.py
  @@ -1,7 +1,7 @@
   from numpy import linspace, sin
   
  -from enable.api import ColorTrait
  -from chaco.api import ArrayPlotData, Plot, marker_trait
  +from enable.api import ColorTrait, marker_trait
  +from chaco.api import ArrayPlotData, Plot
   from enable.api import ComponentEditor
   from traits.api import HasTraits, Instance, Int
   from traitsui.api import Group, Item, View
  
verification_info: {"golden_diff": "diff --git a/examples/tutorials/scipy2008/traits_example.py b/examples/tutorials/scipy2008/traits_example.py\n--- a/examples/tutorials/scipy2008/traits_example.py\n+++ b/examples/tutorials/scipy2008/traits_example.py\n@@ -1,7 +1,7 @@\n from numpy import linspace, sin\n \n-from enable.api import ColorTrait\n-from chaco.api import ArrayPlotData, Plot, marker_trait\n+from enable.api import ColorTrait, marker_trait\n+from chaco.api import ArrayPlotData, Plot\n from enable.api import ComponentEditor\n from traits.api import HasTraits, Instance, Int\n from traitsui.api import Group, Item, View\n", "issue": "ImportError: cannot import name 'marker_trait' from 'chaco.api'\n**Problem Description**\nImportError: cannot import name 'marker_trait' from 'chaco.api' when trying to run a 2008 demo\n\n**Reproduction Steps:**\n\n```python\npython chaco/examples/tutorials/scipy2008/traits_example.py\n```\n\n**Expected behavior:**\ntest past\n\n**OS, Python version:** [MacOS, python3.8 (with or without edm) or 3.11]\n\n", "before_files": [{"content": "from numpy import linspace, sin\n\nfrom enable.api import ColorTrait\nfrom chaco.api import ArrayPlotData, Plot, marker_trait\nfrom enable.api import ComponentEditor\nfrom traits.api import HasTraits, Instance, Int\nfrom traitsui.api import Group, Item, View\n\n\nclass ScatterPlotTraits(HasTraits):\n\n    plot = Instance(Plot)\n    color = ColorTrait(\"blue\")\n    marker = marker_trait\n    marker_size = Int(4)\n\n    traits_view = View(\n        Group(\n            Item(\"color\", label=\"Color\", style=\"custom\"),\n            Item(\"marker\", label=\"Marker\"),\n            Item(\"marker_size\", label=\"Size\"),\n            Item(\"plot\", editor=ComponentEditor(), show_label=False),\n            orientation=\"vertical\",\n        ),\n        width=800,\n        height=600,\n        resizable=True,\n        title=\"Chaco Plot\",\n    )\n\n    def __init__(self):\n        # Create the data and the PlotData object\n        x = linspace(-14, 14, 100)\n        y = sin(x) * x ** 3\n        plotdata = ArrayPlotData(x=x, y=y)\n        # Create a Plot and associate it with the PlotData\n        plot = Plot(plotdata)\n        # Create a line plot in the Plot\n        self.renderer = plot.plot((\"x\", \"y\"), type=\"scatter\", color=\"blue\")[0]\n        self.plot = plot\n\n    def _color_changed(self):\n        self.renderer.color = self.color\n\n    def _marker_changed(self):\n        self.renderer.marker = self.marker\n\n    def _marker_size_changed(self):\n        self.renderer.marker_size = self.marker_size\n\n\n# ===============================================================================\n# demo object that is used by the demo.py application.\n# ===============================================================================\ndemo = ScatterPlotTraits()\n\nif __name__ == \"__main__\":\n    demo.configure_traits()\n", "path": "examples/tutorials/scipy2008/traits_example.py"}]}