How to set two attributes for the norm parameter in a pcolormesh?

When using pcolormesh, I need to set the color range, so I use
norm=[mcolors.BoundaryNorm(np.arange(-0.3,0.6+0.1,0.1),, extend='both')] .
However I aslo want to set norm = mcolors.TwoSlopeNorm(vcenter=0) . How can I set these two attributes in pcolormesh at the same time?

I do not fully understand the question. ScalarMappable objects have exactly 1 norm both conceptually and at the code level.

What are you trying to do that you want to set two norms?