<｜begin▁of▁sentence｜>### Instruction:
Given a directed graph stored in 'directed_graph.gml', how can you modify the visual representation of the graph to have uniform arrow sizes for all edges using igraph's EdgeCollection.set_arrow_size function?
### Response:
from igraph import Graph

# Read a directed graph from a file
g = Graph.Read_GML('directed_graph.gml')

# Set the arrow sizes for the visual representation of the graph
g.es.set_arrow_size(0.5)

# Draw the graph with the specified arrow sizes
g.draw('graph_with_custom_arrows.png')
<|EOT|>
