Several Net::HTTP methods raise Net::* exceptions but the doc claims they will not

[cbetti]

This applies to all the flavors of request_VERB, but here are a few examples of Net::* exceptions being raised with Net::HTTP#request_post, run against MRI Ruby 2.5.5. I suspect any exception which would not be represented by a legitimate HTTP response falls into this category:

Net::OpenTimeout

	 8: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1412:in `request_post'
	 7: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1458:in `request'
	 6: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:909:in `start'
	 5: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:920:in `do_start'
	 4: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:935:in `connect'
	 3: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/timeout.rb:103:in `timeout'
	 2: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:937:in `block in connect'
	 1: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:937:in `open'
/home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:937:in `initialize': execution expired (Net::OpenTimeout)

Net::ReadTimeout

	12: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1412:in `request_post'
	11: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1458:in `request'
	10: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:910:in `start'
	 9: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1460:in `block in request'
	 8: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1467:in `request'
	 7: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1494:in `transport_request'
	 6: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1494:in `catch'
	 5: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1497:in `block in transport_request'
	 4: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http/response.rb:29:in `read_new'
	 3: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http/response.rb:40:in `read_status_line'
	 2: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/protocol.rb:167:in `readline'
	 1: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/protocol.rb:157:in `readuntil'
/home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/protocol.rb:181:in `rbuf_fill': Net::ReadTimeout (Net::ReadTimeout)

It may be worth noting in the doc that other communications-related exceptions are raised, though this is not a strict doc contradiction:

Errno::ENETUNREACH

	 8: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1412:in `request_post'
	 7: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:1458:in `request'
	 6: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:909:in `start'
	 5: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:920:in `do_start'
	 4: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:935:in `connect'
	 3: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/timeout.rb:103:in `timeout'
	 2: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/timeout.rb:93:in `block in timeout'
	 1: from /home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:936:in `block in connect'
/home/chrisbetti/.rvm/rubies/ruby-2.5.5/lib/ruby/2.5.0/net/http.rb:939:in `rescue in block in connect': Failed to open TCP connection to 203.0.113.1:80 (Network is unreachable - connect(2) for "203.0.113.1" port 80) (Errno::ENETUNREACH)

I spot-checked Ruby 2.5.5 and 2.7.1 documentation, and the documentation error is present in both places.