public static boolean isNotTrue(final Boolean bool) {
        return !isTrue(bool);
    }
<p>Checks if a {@code Boolean} value is <i>not</i> {@code true},
handling {@code null} by returning {@code true}.</p>

<pre>
  BooleanUtils.isNotTrue(Boolean.TRUE)  = false
  BooleanUtils.isNotTrue(Boolean.FALSE) = true
  BooleanUtils.isNotTrue(null)          = true
</pre>

@param bool  the boolean to check, null returns {@code true}
@return {@code true} if the input is null or false
@since 2.3
fastexcel-core/src/main/java/cn/idev/excel/util/BooleanUtils.java