This interface defines an object which can be used to set values
to be used to control the PDF library - turning on or off debug
flags, controlling the location of additional software and so on.
Until 2.8.5 this class didn't exist and these values were
determined by calling System.getProperty(nnn)
instead, but this class allows those values to be more easily
specified in servlets, applets and other environments where modifying
the System properties isn't always appropriate or possible.
Defines a PropertyManager which checks the System.getProperty(java.lang.String)
method. A call to getProperty(key) will return
the value of
This PropertyManager is the default one used by the PDF library.