def select_source(self, source):
status = self.status()<EOL>if status['<STR_LIT>']:  <EOL><INDENT>if status['<STR_LIT:source>'] != source:  <EOL><INDENT>if source in self.SOURCES:<EOL><INDENT>self._send(self.CMD_SOURCE + self.SOURCES[source], read_reply=True)<EOL><DEDENT><DEDENT><DEDENT>
Select a source from the list of sources.