src/main/java/com/simpligility/maven/plugins/android/phase04processclasses/ProguardMojo.java
private File getJVMLibrary( String fileName )
    {
        File libFile = new File( getJavaLibDir(), fileName );
        if ( !libFile.exists() )
        {
            libFile = new File( getAltJavaLibDir(), fileName );
            if ( !libFile.exists() )
            {
                libFile = null;
            }
        }
        return libFile;
    }
private File getJVMLibrary( String fileName )
    {
        File libFile = new File( getJavaLibDir(), fileName );
        if ( !libFile.exists() )
        {
            libFile = new File( getAltJavaLibDir(), fileName );
            if ( !libFile.exists() )
            {
                libFile = null;
            }
        }
        return libFile;
    }
Finds a library file in either the primary or alternate lib directory.
@param fileName The base name of the file.
@return Either a canonical filename, or {@code null} if not found.