GraphPropertyDistribution
GraphPropertyDistribution[expr, x \[Distributed] gdist] represents the distribution of the property expr where the random variable x follows the graph distribution gdist.
GraphPropertyDistribution[expr, {x1 \[Distributed] gdist1, x2 \[Distributed] gdist2, ...}] represents the distribution where x1, x2, ... are independent and follow the graph distributions gdist1, gdist2, ....
Examples
Define a distribution of vertex counts:
GraphPropertyDistribution[VertexCount[g], g \[Distributed] RandomGraph[{10, 20}]]Please visit the official Wolfram Language Reference for more details.