<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_default_formatters(self, which=None):
 """Sets the default formatters that is used for updating to None Parameters which: {None, 'minor', 'major'} Specify which locator shall be set"""

        if which is None or which == 'minor':
            self.default_formatters['minor'] = self.axis.get_minor_formatter()
        if which is None or which == 'major':
            self.default_formatters['major'] = self.axis.get_major_formatter()