Trend block, how/where it is implemented?

[1337kerberos]

I like how this library detects/displays a trend block. I'm looking for the logic handling it, but I can't find it.
To be more precise, this is about a green/red background block, as in the attached picture. Thanks!)

[1337kerberos]

I found it, and it is not a trend block... it is controlled by a parameter superimpose=True