key - the key to be placed into this property list.
value - the value corresponding to the key.
the previous value of the specified key in this property list, or
null if it did not have one.
public java.lang.String getProperty(java.lang.String key)
Searches for the property with the specified key in the property lists. If
the property is not found in any map of properties, then the method returns
Different property maps of properties exist. The order in which they are
searched in is:
In the case a property value is set to null, then it is considered as
non-existent in its map and the search goes on, possibly returning a
shared-property sharing the same key.