<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_tool(name):
 """ Returns an instance of a specific tool. Parameters name : str Name of the tool (case-insensitive). Returns ------- tool : MotifProgram instance """

    tool = name.lower()
    if tool not in __tools__:
        raise ValueError("Tool {0} not found!\n".format(name))

    t = __tools__[tool]()

    if not t.is_installed():
        sys.stderr.write("Tool {0} not installed!\n".format(tool))

    if not t.is_configured():
        sys.stderr.write("Tool {0} not configured!\n".format(tool))

    return t