<｜begin▁of▁sentence｜>### Instruction:
As an Endocrinologist, you may encounter a scenario where you need to visually represent a patient's thyroid hormone levels and their impact on various systems in the body. In this situation, you might be interested in drawing directed edges with varying transparency levels (alpha) based on the levels of thyroid hormone attributes in a network representing the body's systems. To achieve this, you can consider implementing a custom edge drawer class in networkx, allowing you to visually represent the impact of thyroid hormone levels on different systems within the body network graph.
### Response:
import igraph as ig
from igraph.drawing.text import TextDrawer
from igraph.drawing import plot

class AlphaVaryingEdgeDrawer(ig.drawing.edges.EdgeDrawer):
    def draw_directed_edge(self, edge, src_vertex, dest_vertex):
        # Custom directed edge drawing logic
        pass

# Create a graph
g = ig.Graph([(0, 1), (1, 2)])
g.vs['label'] = ['A', 'B', 'C']  # Vertex labels
g.es['label'] = ['AB', 'BC']    # Edge labels

# Create a plot with custom edge drawer
plot(g, 'output.png', edge_drawer=AlphaVaryingEdgeDrawer)
<|EOT|>
