<｜begin▁of▁sentence｜>### Instruction:
As an archivist appraising historical documents and records, imagine being tasked with creating a digital image to accompany an important historical document. The image should feature a single blue rectangle on a white background, and it needs to be saved as a PNG file for preservation purposes. In this scenario, you are looking for guidance on utilizing Cairo's context methods to draw the rectangle and save the resulting image.
### Response:
import cairo

# Create a surface object to draw on
width, height = 640, 480
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)

# Create a context for the surface
cr = cairo.Context(surface)

# Draw a blue rectangle
cr.set_source_rgb(0, 0, 1)  # Blue
cr.rectangle(10, 10, 100, 100)  # Rectangle(x, y, width, height)
cr.fill()

# Output the result to a file
output_filename = 'output.png'
surface.write_to_png(output_filename)
print(f'Saved drawing to {output_filename}')
<|EOT|>
