public long getUnsignedLong(DWARFAttribute attribute, long defaultValue) {
		DWARFNumericAttribute attr = getAttribute(attribute, DWARFNumericAttribute.class);
		return (attr != null) ? attr.getUnsignedValue() : defaultValue;
	}
Returns the unsigned long integer value of the requested attribute, or -defaultValue-
if the attribute is missing.
<p>
The 'unsigned'ness of this method refers to how the binary value is read from
the dwarf information (ie. a value with the high bit set is not treated as signed).
<p>
The -defaultValue- parameter can accept a negative value.

@param attribute {@link DWARFAttribute} id
@param defaultValue value to return if attribute is not present
@return unsigned long value, or the defaultValue if attribute is not present
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DIEAggregate.java