<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def cvpool(agent):
 """ Indicate whether or not any watched kernel variables that have a specified agent on their notification list have been updated. http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/cvpool_c.html :param agent: Name of the agent to check for notices. :type agent: str :return: True if variables for "agent" have been updated. :rtype: bool """

    agent = stypes.stringToCharP(agent)
    update = ctypes.c_int()
    libspice.cvpool_c(agent, ctypes.byref(update))
    return bool(update.value)