How to use the pbxproj.pbxsections.PBXBuildFile.PBXBuildFile.create function in pbxproj

def testRemoveAttributesWithoutSettings(self):
        dobj = PBXBuildFile.create(PBXGenericObject())

        dobj.remove_attributes('Weak')

        self.assertIsNone(dobj[u'settings'])

def testRemoveAttributesWithSettings(self):
        dobj = PBXBuildFile.create(PBXGenericObject(), attributes=["Weak"])

        dobj.remove_attributes('Weak')

        self.assertIsNone(dobj[u'settings'])

def testAddAttributesWithAttributes(self):
        dobj = PBXBuildFile.create(PBXGenericObject(), attributes="x")
        dobj.add_attributes(u'Weak')

        self.assertIsNotNone(dobj.settings.ATTRIBUTES)
        self.assertEquals(dobj.settings.ATTRIBUTES, [u'x', u'Weak'])

def testAddAttributesWithoutAttributes(self):
        dobj = PBXBuildFile.create(PBXGenericObject(), compiler_flags="x")

        dobj.add_attributes(u'Weak')

        self.assertIsNotNone(dobj.settings.ATTRIBUTES)
        self.assertEquals(dobj.settings.ATTRIBUTES, [u'Weak'])

def testAddAttributesWithoutSettings(self):
        dobj = PBXBuildFile.create(PBXGenericObject())

        dobj.add_attributes(u'Weak')

        self.assertIsNotNone(dobj.settings.ATTRIBUTES)
        self.assertEquals(dobj.settings.ATTRIBUTES, [u'Weak'])

def testAddCompilerFlagWithFlags(self):
        dobj = PBXBuildFile.create(PBXGenericObject(), compiler_flags=[u'Weak', '-fno-arc'])

        dobj.add_compiler_flags('x')

        self.assertIsNotNone(dobj.settings.COMPILER_FLAGS)
        self.assertEquals(dobj.settings.COMPILER_FLAGS, u'Weak -fno-arc x')

def testRemoveCompilerFlagsWithSettings(self):
        dobj = PBXBuildFile.create(PBXGenericObject(), compiler_flags=u'Weak')

        dobj.remove_compiler_flags('Weak')

        self.assertIsNone(dobj[u'settings'])

def testAddCompilerFlagWithoutSettings(self):
        dobj = PBXBuildFile.create(PBXGenericObject())

        dobj.add_compiler_flags([u'Weak', '-fno-arc'])

        self.assertIsNotNone(dobj.settings.COMPILER_FLAGS)
        self.assertEquals(dobj.settings.COMPILER_FLAGS, u'Weak -fno-arc')

def testRemoveCompilerFlagsWithoutSettings(self):
        dobj = PBXBuildFile.create(PBXGenericObject())

        dobj.remove_compiler_flags('Weak')

        self.assertIsNone(dobj[u'settings'])