def get_content(uri, query = nil, extheader = {}, &block)
    follow_redirect(uri, query) { |uri, query|
      get(uri, query, extheader, &block)
    }.content
  end
def get_content(uri, query = nil, extheader = {}, &block)
    follow_redirect(uri, query) { |uri, query|
      get(uri, query, extheader, &block)
    }.content
  end
SYNOPSIS
   Client#get_content(uri, query = nil, extheader = {}, &block = nil)

 ARGS
   uri       an_URI or a_string of uri to connect.
   query     a_hash or an_array of query part.  e.g. { "a" => "b" }.
             Give an array to pass multiple value like
             [["a" => "b"], ["a" => "c"]].
   extheader a_hash of extra headers like { "SOAPAction" => "urn:foo" }.
   &block    Give a block to get chunked message-body of response like
             get_content(uri) { |chunked_body| ... }
             Size of each chunk may not be the same.

 DESCRIPTION
   Get a_sring of message-body of response.