public String getLowerLimit()
    {
        String retval = null;
        COSArray arr = node.getCOSArray(COSName.LIMITS);
        if( arr != null )
        {
            retval = arr.getString( 0 );
        }
        return retval;
    }
@Test
    void testLowerLimit() throws IOException
    {
        assertEquals("Actinium", this.node5.getLowerLimit());
        assertEquals("Actinium", this.node2.getLowerLimit());

        assertEquals("Xenon", this.node24.getLowerLimit());
        assertEquals("Xenon", this.node4.getLowerLimit());

        assertEquals(null, this.node1.getLowerLimit());
    }