title: How to solve no signature of method with groovy in a jenkins pipeline
body: <p>I have a multi line script</p>
  
  <pre><code>sh """
          SCRIPT_BRANCH=${SCRIPT_BRANCH:-develop}
          curl -o ${LIQUIBASE_CI_SCRIPT} -H "Authorization: token ${GITHUB_AUTH_TOKEN}" --header ${SCRIPT_BRANCH}/src/shell/branch_cut_liquibase_gen.sh
          chmod +x ${LIQUIBASE_CI_SCRIPT}
          curl -o ${LIQUIBASE_GEN_SCRIPT} -H "Authorization: token ${GITHUB_AUTH_TOKEN}" --header ${SCRIPT_BRANCH}/src/shell/liquibase_generation.sh
          chmod +x ${LIQUIBASE_GEN_SCRIPT}
          curl -o ${LIQUIBASE_TRANSFORM_SCRIPT} ${SCRIPT_BRANCH}/src/python/liquibase_transform.py
          chmod +x ${LIQUIBASE_TRANSFORM_SCRIPT} 
          ${LIQUIBASE_CI_SCRIPT}
      """.stripMargin()
  
      email(${EMAIL}, ${DEFAULT_CONTENT})
  
  def build = bareBuild() {
      buildAction = branchCutAction
  }
  </code></pre>
  
  <p>like so within my groovy file. It's being called by jenkins and I am getting this error. </p>
  
  <pre><code>hudson.remoting.ProxyException: groovy.lang.MissingMethodException: No signature of method: java.lang.String.negative() is applicable for argument types: () values: []Possible solutions: notify(), normalize(), next()
  </code></pre>
  
  <p>I'm really at a loss as to why this can be the case. I've looked through similar questions and nothing seems to match up with my issue</p>