Plot labels inconsistency

[WarpGate795]

Hi, I was recently working on DER and found that Annotation shows inconsistency between plot and legend when tensors are used.
For example,

from pyannote.core import Annotation, Segment
import torch
import numpy as np

annotation = Annotation()
for i in range(10):
    annotation[Segment(i, i + 1)] = torch.tensor(0)
annotation

Executing the above code would produce the following output

However assigning int 0 rather tensor produces the accurate plot,

If only numpy data is being handled properly, there is no exception generated when tensors are used.