agree with andrew's answer above. When using a function call in ruby, you can either have a space with no parenthesis, or parenthesis and no space, but not both. so:
pdf.bounding_box([80, 510] , :width => 400)
is ok
pdf.bounding_box [80, 510] , :width => 400
is also ok
But you can't do a space and a parenthesis. Now in your case, since you want to chain the result of this to a do/end block, you will have to use the parenthesis, so option 1 is the only way to go.
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