I am getting the below error, please help me to resolve it

http://gmail.com
FAILED: testB
java.lang.NoSuchMethodError: com.google.common.base.Preconditions.checkState(ZLjava/lang/String;Ljava/lang/Object;)V
at org.openqa.selenium.remote.service.DriverService.checkExecutable(DriverService.java:146)
at org.openqa.selenium.firefox.GeckoDriverService.access$000(GeckoDriverService.java:44)
at org.openqa.selenium.firefox.GeckoDriverService$Builder.usingFirefoxBinary(GeckoDriverService.java:160)
at org.openqa.selenium.firefox.FirefoxDriver.toExecutor(FirefoxDriver.java:187)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:147)
at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:125)
at com.selenium.core.ddf.base.BaseTest.openBrowser(BaseTest.java:33)
at com.selenium.core.ddf.testcases.DummyTestB.testB(DummyTestB.java:12)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:639)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:821)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1131)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:124)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
at org.testng.TestRunner.privateRun(TestRunner.java:773)
at org.testng.TestRunner.run(TestRunner.java:623)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:357)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:352)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:310)
at org.testng.SuiteRunner.run(SuiteRunner.java:259)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1185)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1110)
at org.testng.TestNG.run(TestNG.java:1018)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:236)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:81)