Text Searching in FlowGraph

[XYlearn]

FlowGraph is usually leveraged to show customized graphs. When the graph is large, finding interesting block becomes harder and time-wasting. However, I haven't found document about how to search texts in the FlowGraph. Even worse, when a FlowGraph is shown without saving its handle, it's hard to implement a searching interface, because there is no current_flowgraph variable capture the FlowGraph context.

[plafosse]

This is unfortunately a known deficiency with the existing search interfaces. We plan to address this at some point but have no firm timeline. #2197