check_connection return False if not overridden (makes sense as it is generally impossible to know if the instrument has been tampered with).
Add a pre_get hook and make default_check_instrument_operation take value and i_value as args (might be useful in some cases).
Add possibility to declare assertion to be tested before getting/setting through the checks kwarg. One can declare symmetric assertion using a single string or asymetric using a tuple, multiple assertions can be separated by ; . No support for mathematical function.
Update test to more recent developments.