official, pro forma sleep

[Sukhomvit]

"Kinanjui in these meetings had a manner of his own: when he thought that the discussions were dragging out too long, he leant back in his chair, and, while still keeping the fire in his cigar alive, he closed his eyes and drew his breath deeply and slowly, in a low regular snore, a sort of official, pro forma sleep, which he may have cultivated for use in his own Council of State"

(Out of Africa by I. Dinensen)​

The author describes a Kikuyu (african) Chief. I do not fully understand underlined words. Is that means: "similar to a kind of sleep in office?"
Please a teacher or member help me out. Thank you for your hint.

 

[Tdol]

It suggests to me that sleeping like that was to be expected from someone in this position.

 

[Sukhomvit]

It suggests to me that sleeping like that was to be expected from someone in this position.

Thanks Tdol. If possible please kindly explain meaning of each word: "a sort of official" and "pro forma".

 

[teechar]

Take a look at the following links.

http://dictionary.cambridge.org/dictionary/english/sort-of

http://dictionary.cambridge.org/dictionary/english/pro-forma