info about HandlerCall::call_read()

Hi list,

I have created an element called WC.
In a configuration .click file i have a bank of 5 WC elements (WC1,
WC2...WC5),  each one of them with a read handler called "energy".
I would like to create a control element CONTROL which reads the handler
"energy" on the desired WC and make some calculations with it.
I'm trying with this function to call the handler, but i don't manage to
find how to use it in a correct way:

String <http://www.read.cs.ucla.edu/click/doxygen/class_string.html>HandlerCall::call_read
( Element <http://www.read.cs.ucla.edu/click/doxygen/class_element.html> *
*e*,

const String <http://www.read.cs.ucla.edu/click/doxygen/class_string.html>&
*hname*,

ErrorHandler<http://www.read.cs.ucla.edu/click/doxygen/class_error_handler.html>*
*errh* = 0
)

Any ideas or suggestions?

Thanks!