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I'm back in our workspaces project and
we're ready to use our doc annotation and

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the MathUtils class.

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First, we'll need to import
the annotation itself,

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import com.teamtreehouse.docgen.Doc.

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We'll start by applying
the annotation to the class itself.

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And in this annotation, we'll need
to include just a description since

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parameters and
return types will not apply to the class.

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You can list the annotation on separate
lines if you'd like to keep it well

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formatted.

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I'll say that this is a Utility class for
commonly used math functions.

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Notice that I've had to
explicitly list D-E-S-C.

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Remember, the only time you can omit
the element name is when the element name

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is exactly value.

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Now, let's add some annotations to a few
methods and make some of them incomplete

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just to verify that our tool is able
to catch both successes and failures.

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For the triangle area method, I'll include
a description for only one parameter.

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So include our doc annotation,
I'll put this on three separate lines.

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For the description, I'll write that
it calculates the area of a triangle.

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I'll abbreviate here.

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For the parameters, again, I will include
a description for just one parameter.

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And again,
our params element is a string array, so

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I'll have to use array notation
with the curly braces.

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And for the returnVal, I will say returns
the calculated area of the triangle.

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Cool.

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For the distance method,
I'll make the returnVal an empty string.

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I'll include as its
description that it calculates

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the distance between the given points.

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I'll include descriptions for
both parameters,

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the first one being
the coordinates of one point,

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the second one being
the coordinates of another point.

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And finally, the returnVal, as I said,
I will leave as an empty string.

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As for the quadraticRoots method,
I'll leave this one out completely and

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go right to the epsilon method.

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For this one, I'll include only a
description since it has no parameters and

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is a void method.

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I'll say that this displays
the value of epsilon.

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The arePointsClose method
won't need documentation

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to pass our tools test since
it's a private method.

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And there you have it,

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a class that utilizes the annotation
that we wrote ourselves.

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The writing of the doc
annotation was fairly brief.

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The lengthier work for us will come in
the form of examining the presence of our

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annotation on classes and methods
through a technique called reflection.

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More on that next.