<｜begin▁of▁sentence｜>### Instruction:
Given a simple undirected graph object `g`, with vertices labeled 'A', 'B', and 'C', and edges connecting each pair of vertices, how can you use a custom edge drawer that extends `AbstractCairoDrawer` to plot the graph with straight lines representing the edges?
### Response:
import igraph as ig
from igraph.drawing.text import TextDrawer
from igraph.drawing.baseclasses import AbstractCairoDrawer

# Draw the undirected edges of a graph

class MyEdgeDrawer(AbstractCairoDrawer):
    def draw_undirected_edge(self, edge, src_vertex, dest_vertex):
        cr = self.context
        cr.move_to(src_vertex['x'], src_vertex['y'])
        cr.line_to(dest_vertex['x'], dest_vertex['y'])
        cr.stroke()

# Example usage
# Create a simple graph
g = ig.Graph([(0, 1), (1, 2), (2, 0)])
# Set up plotting
visual_style = {}
visual_style['vertex_size'] = 0.2
visual_style['vertex_label'] = ['A', 'B', 'C']
# Plot the graph
ig.plot(g, **visual_style, edge_drawer=MyEdgeDrawer)
<|EOT|>
