public function testGetSystemVariableDefinitions()
 {
     $provider1 = $this->getMock('Oro\\Bundle\\EmailBundle\\Provider\\SystemVariablesProviderInterface');
     $provider1->expects($this->once())->method('getVariableDefinitions')->will($this->returnValue(['var1' => ['type' => 'string', 'label' => 'var1'], 'var3' => ['type' => 'string', 'label' => 'var3']]));
     $provider2 = $this->getMock('Oro\\Bundle\\EmailBundle\\Provider\\SystemVariablesProviderInterface');
     $provider2->expects($this->once())->method('getVariableDefinitions')->will($this->returnValue(['var2' => ['type' => 'string', 'label' => 'var2']]));
     $this->provider->addSystemVariablesProvider($provider1);
     $this->provider->addSystemVariablesProvider($provider2);
     $result = $this->provider->getSystemVariableDefinitions();
     $this->assertSame(['var1' => ['type' => 'string', 'label' => 'var1'], 'var2' => ['type' => 'string', 'label' => 'var2'], 'var3' => ['type' => 'string', 'label' => 'var3']], $result);
 }