def get_tool_filepath(self, tool_alias):
tools_dict = self.get_tools()<EOL>if tool_alias in tools_dict:<EOL><INDENT>if self.tools_path is None:<EOL><INDENT>return None<EOL><DEDENT>else:<EOL><INDENT>return os.path.join(self.tools_path, tool_alias)<EOL><DEDENT><DEDENT>else:<EOL><INDENT>return None<EOL><DEDENT>
Given a visible tool alias, return the full path to the executable.

        Args:
            tool_alias (str): Tool alias to search for.

        Returns:
            (str): Filepath of executable, or None if the tool is not in the
                suite. May also return None because this suite has not been saved
                to disk, so a filepath hasn't yet been established.