title: Groovy - No signature of method: groovy.util.slurpersupport.NodeChildren.isArray()
body: <p>I'm writing a program that would arm/disarm my home and everything executes properly, but I keep on getting the following error message at the end of execution.</p>
  
  <p>groovy.lang.MissingMethodException: No signature of method: groovy.util.slurpersupport.NodeChildren.isArray() is applicable for argument types: () values: []
  Possible solutions: isEmpty(), every()</p>
  
  <p>My code is </p>
  
  <pre><code>def disarm() {
      log.debug "During disarming. SessionID: ${state.token}"
      if(state.token) {
  
          def paramsDisarm = [
              uri: "URL",
              body: [SessionID: state.token, LocationID: location, DeviceID: deviceID, UserCode: usercode]
              ]
              httpPost(paramsDisarm) { responseDisarm -&gt;
              log.debug "Code is ${responseDisarm.data.ResultCode}"
              log.debug "Message: ${responseDisarm.data.ResultData}"  
              sendPush("Home is now Disarmed")
              }
         log.debug "Is this getting executed?"
         logout()
      }
      else
      {
      log.debug "Smart Things is not logged in. Need to login"
          login()
          disarm()
      }
  
  }
  </code></pre>
  
  <p>My logout call is </p>
  
  <pre><code>def logout() {
      log.debug "During logout - ${state.token}"
      def paramsLogout = [
              uri: "URL",
              body: [SessionID: state.token]
              ]
              httpPost(paramsLogout) { responseLogout -&gt;
              log.debug "Smart Things has successfully logged out"
          }  
  }
  </code></pre>
  
  <p>Looking at the console log, I see everything is executed quite well. Here is the console log.</p>
  
  <pre><code>8:58:41 PM: error groovy.lang.MissingMethodException: No signature of method: groovy.util.slurpersupport.NodeChildren.isArray() is applicable for argument types: () values: []
  Possible solutions: isEmpty(), every()
  8:58:41 PM: debug Smart Things has successfully logged out
  8:58:40 PM: debug During logout - 65103122-1915-49C2-A021-015871AD7C93
  8:58:40 PM: debug Is this getting executed?
  8:58:40 PM: debug Message: Session Initiated. Poll for command state update
  8:58:40 PM: debug Code is 4500
  8:58:36 PM: debug During disarming. 65103122-1915-49C2-A021-015871AD7C93
  8:58:36 PM: debug Smart Things has logged In. SessionID: '65103122-1915-49C2-A021-015871AD7C93'
  8:58:32 PM: debug Smart Things is not logged in. Need to login
  8:58:32 PM: debug During disarming. SessionID: null
  8:58:32 PM: debug Mode is set to Home, Performing Disarm
  </code></pre>
  
  <p>My code runs fine and does what it should, but the error message still bugs me.</p>