Drawing Book

After his sister Jensene finished the coloring book, Chris bought another drawing book for her. The first page of the book contains a diagram

There are 9 vertices from $$A$$ to $$I$$. How many ways are there to trace the figure without lifting the pen such that it passes through all the vertices and each edge is drawn at most once?

Clarification: Chris does not have to draw pass every edge.

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