constructor from a PoolName (integer like) object and a function
# S4 method for `function`,character
OutFlux_by_PoolName(func, sourceName)
A function. The names of the formal arguments have to be a subset of the state variable names and the time symbol
the name of the source pool This allows subsequent automatic reordering of the state variables. In the presence of a vector of stave variable names the formulation can automatically be transformed to a function of a state VECTOR argument and #' time constructor from an ordered pair of PoolName (integer like) objects