<｜begin▁of▁sentence｜>### Instruction:
Given a plotting surface from igraph's Plot class, how can you use the CairoTextDrawer object to set a specific text at the center alignment, and also clear the text by passing None?
### Response:
from igraph.drawing.text import CairoTextDrawer
from igraph import Plot

# Create a Plot surface
plot = Plot(surface=None)

# Define the text drawer
ctd = CairoTextDrawer(plot.ca, halign=CairoTextDrawer.CENTER)

# Set the text to be drawn
text_to_draw = 'Hello, World!'
ctd.text(text_to_draw)

# You can also pass None to clear the text
text_to_clear = None
ctd.text(text_to_clear)
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