Fabricjs line coordinates after movement

sequencing:

1. draw the line at coordinates (x1 = 50, y1 = 50, x2 = 450, y2 = 50)

2. Checking coordinate y1. y1 = 50

3. Move the line on the y-axis by 50 pixels.

4. Checking coordinate y1. LEFT y1 = 50 ??? Why is that? And how to get the true coordinates?

fiddle