@Override
            public boolean accept(File file) {
                return file.isFile() && file.getName().endsWith(EXTENSION_SUFFIX);
            }
Returns a list of all installed extensions in the order they should be
loaded. Extension load order is dictated by the "extension-priority"
property and by extension filename. Each extension within
GUACAMOLE_HOME/extensions is read and validated, but not fully loaded.
It is the responsibility of the caller to continue the load process with
the extensions in the returned list.

@return
    A list of all installed extensions, ordered by load priority.
guacamole/src/main/java/org/apache/guacamole/extension/ExtensionModule.java