Edges sometimes facing wrong direction with multiple edges between the same pair of nodes

[ablumenf]

When using curvestyle="curved", arrows sometimes point the wrong direction. Example:

from diagrams import Diagram
from diagrams.aws.storage import S3 as Data

with Diagram(filename="test1", show=False, direction="TB", curvestyle="curved"):

    A = Data("A")
    B = Data("B")

    A >> B
    B >> A

I end up seeing two A >> B arrows instead of what I want. To fix it, I need to change the second one to A << B or change curvestyle to "ortho". The first solution is more difficult when visualizing graphs from computed graphs programmatically, I probably need to know which node is "higher," which is likely inconsistent with graph visualization algorithms. (I tried this and had my loop going the right direction, but there ended up being a loop that shouldn't have been there when there should have been 2 arrows from the same input node to the same output node.)