Searches for the property with the specified key in this property list.
If the key is not found in this property list, the default property list,
and its defaults, recursively, are then checked. The method returns
{@code null} if the property is not found.
@param key the property key.
@return the value in this property list with the specified key value.
Searches for the property with the specified key in this property list. If the key is not found in this property list, the default property list, and its defaults, recursively, are then checked. The method returns {@code null} if the property is not found.
@param key the property key. @return the value in this property list with the specified key value.