@classmethod<EOL><INDENT>def validate_proxies_config(cls, proxies):<DEDENT>
for name, proxy in six.iteritems(proxies):<EOL><INDENT>if "<STR_LIT:port>" not in proxy:<EOL><INDENT>raise ValueError("<STR_LIT>" % name)<EOL><DEDENT>if "<STR_LIT>" not in proxy:<EOL><INDENT>raise ValueError(<EOL>"<STR_LIT>" % name<EOL>)<EOL><DEDENT>for upstream in proxy["<STR_LIT>"]:<EOL><INDENT>if "<STR_LIT:host>" not in upstream:<EOL><INDENT>raise ValueError(<EOL>"<STR_LIT>" % name<EOL>)<EOL><DEDENT>if "<STR_LIT:port>" not in upstream:<EOL><INDENT>raise ValueError(<EOL>"<STR_LIT>" % name<EOL>)<EOL><DEDENT><DEDENT><DEDENT>
Specific config validation method for the "proxies" portion of a
config.

Checks that each proxy defines a port and a list of `upstreams`,
and that each upstream entry has a host and port defined.