@link
org.objectweb.asm.ClassWriter ClassWriter} class is necessary. Indeed,
in order to generate a class, one must just call its visit<i>Xxx</i>
methods with the appropriate arguments to generate the desired fields
and methods.

<p>
In order to modify existing classes, one must use a {@link
org.objectweb.asm.ClassReader ClassReader} class to analyze
the original class, a class modifier, and a {@link org.objectweb.asm.ClassWriter
ClassWriter} to construct the modified class. The class modifier
is just a {@l