in src/main/java/org/apache/maven/plugin/docck/AbstractCheckDocumentationMojo.java [514:521]
private void checkFile( String url, String description, DocumentationReporter reporter )
{
File licenseFile = new File( url );
if ( !licenseFile.exists() )
{
reporter.error( "The " + description + " in file \'" + licenseFile.getPath() + "\' does not exist." );
}
}