<｜begin▁of▁sentence｜>### Instruction:
Given a graph generated by Graph.Tree(127, 2), can you use CairoDendrogramDrawer with a specified bounding box size and a given palette to draw the dendrogram of the graph's community structure obtained by edge betweenness clustering and save it as a PNG image?
### Response:
from igraph import Graph
from igraph.drawing import Plot
from igraph.drawing.graph import CairoDendrogramDrawer
from igraph.drawing.utils import BoundingBox
import cairo

# Loading a graph
graph = Graph.Tree(127, 2)

# Create a dendrogram from the graph
dendrogram = graph.community_edge_betweenness().as_clustering()

# Create a surface to draw on
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, 600, 400)

# Create a plot with a specified bounding box size
bbox = BoundingBox(600, 400)
plot = Plot(surface, bbox)

# Create a dendrogram drawer
context = cairo.Context(surface)
palette = plot.palette
drawer = CairoDendrogramDrawer(context, bbox, palette)

# Draw the dendrogram on the plot
drawer.draw(dendrogram)

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