NoSuchElementException in org.apache.bcel.generic.InvokeInstruction.toString()

java.util.NoSuchElementException
	at java.util.StringTokenizer.nextToken(StringTokenizer.java:349)
	at org.apache.bcel.generic.InvokeInstruction.toString(InvokeInstruction.java:59)

    /**
     * @return mnemonic for instruction with symbolic references resolved
     */
    @Override
    public String toString( final ConstantPool cp ) {
        final Constant c = cp.getConstant(super.getIndex());
        final StringTokenizer tok = new StringTokenizer(cp.constantToString(c), ":");
        return Const.getOpcodeName(super.getOpcode()) + " " + tok.nextToken().replace('.', '/')
                + tok.nextToken();
    }