<｜begin▁of▁sentence｜>### Instruction:
As an SEO Specialist, your website analytics show that users are spending less time on your site due to poor visualization of your network data. To address this, you plan to utilize igraph to create a custom plot of your network graph within a specified bounding box. To achieve this, you're considering integrating the DescartesCoordinateSystem to initialize a coordinate system for the graph. Your goal is to generate a visually appealing plot with a white background and save it as 'coordinate_system_plot.png'.
### Response:
import igraph as ig
from igraph.drawing import Plot
from igraph.drawing.colors import color_to_html
from igraph.drawing.coord import DescartesCoordinateSystem

# Create a simple graph
g = ig.Graph.Tree(5, 2)

# Create a plot with a specific bounding box
custom_bbox = (300, 300)
plot = Plot(bbox=custom_bbox, background='white')

# Initialize the DescartesCoordinateSystem with the plot's context and bounding box
coord_system = DescartesCoordinateSystem(plot.ctx, plot.bbox, bounds=(0, 1, 0, 1))

# Draw the coordinate system (additional drawing code would be needed here)

# Save the plot
plot.save('coordinate_system_plot.png')
<|EOT|>
