lib/ews/soap/exchange_web_service.rb
def build_soap!(&block)
      opts = { :server_version => server_version, :impersonation_type => impersonation_type, :impersonation_mail => impersonation_address }
      opts[:time_zone_context] = @time_zone_context if @time_zone_context
      EwsBuilder.new.build!(opts, &block)
    end
def build_soap!(&block)
      opts = { :server_version => server_version, :impersonation_type => impersonation_type, :impersonation_mail => impersonation_address }
      opts[:time_zone_context] = @time_zone_context if @time_zone_context
      EwsBuilder.new.build!(opts, &block)
    end
Build the common elements in the SOAP message and yield to any custom elements.