public void setProperty(String propertyName, String value, String source)
			throws XmlParseException {
		if (propertyMap.containsKey(propertyName)) {
			throw new XmlParseException("Attempted to overwrite property value for " +
				propertyName + " in contraint node: " + this);
		}
		propertyMap.put(propertyName, new PropertyValue(value, source));
	}
A node in a decision tree.  Each node contains exactly one constraint and a map of property
 values.

@param <T> the type of objects that the constraint operates on.
Ghidra/Framework/Generic/src/main/java/generic/constraint/DecisionNode.java