Find (practical) current source constants, I and R

[courteous]

Homework Statement

A practical current source has a current of $$22 A$$. Loading the source with $$50 \Omega$$ results in terminal voltage of $$390.3 V$$. Obtain the source constants, I and R.

Homework Equations

$$V=I\times R$$

The Attempt at a Solution

In my clumsy picture below, shouldn't $$I_{load}$$ be replaced by the $$I$$ of the "practical current source"? That is, isn't a "practical current source" as a black box, and we can only "see" the outside current?
[PLAIN]http://img51.imageshack.us/img51/1466/dsc01001ni.jpg

Only if I take the current outside as $$I_{load}$$ (and not as the $$I$$ itself) do I get the correct solution:
$$I_{load}=\frac{V}{R_{load}}=\frac{390.3V}{50 \Omega}=7.806 A$$

$$R=\frac{V}{I_R}=\frac{V}{I-I_{load}}=\frac{390.3 V}{22A - 7.806 A}\dot{=}27.5 \Omega$$

 

[jegues]

Everything looks good to me.

 

[courteous]

Except this:

In my clumsy picture above, shouldn't $$I_{load}$$ be replaced by the $$I$$ of the "practical current source"? That is, isn't a "practical current source" as a black box, and we can only "see" the outside current?