<｜begin▁of▁sentence｜>### Instruction:
Given the High-energy theory collaborations graph which you can read from a GML file named hep-th.gml, can you plot the relation between the size of the communities and their internal edge densities after performing community detection using the Louvain and Leiden methods?
### Response:
import networkx as nx
from cdlib import algorithms, viz, evaluation

# Load the High-energy theory collaborations graph
G = nx.read_gml('hep-th.gml')

# Perform community detection using Louvain and Leiden algorithms
coms_louvain = algorithms.louvain(G)
coms_leiden = algorithms.leiden(G)

# Plot the relation between size and internal edge density of the detected communities
lmplot = viz.plot_com_properties_relation(
    [coms_louvain, coms_leiden],
    evaluation.size,
    evaluation.internal_edge_density
    )

# The lmplot can be displayed using lmplot.fig.show() or saved using lmplot.savefig('output.png')
<|EOT|>
