I'm rewriting some of global scripts from var/* files to src/com/... files.

I'm passing in `this` into the constructor, and then using things like `script.sh`, `script.dir`, `script.env.WORKSPACE` etc.

However,

when porting over the scripts, I noticed that `findFiles` seems not to be available from within the new object located in src/*:

```
script.findFiles(glob: '/')

java.lang.NoSuchMethodError: No such DSL method 'findFiles' found among steps [archive, bat, build, catchError, checkout, container, deleteDir, dir, dockerFingerprintFrom, dockerFingerprintRun, dockerLabel, echo, envVarsForTool, error, fileExists, getContext, git, input, isUnix, libraryResource, load, mail, milestone, node, parallel, podTemplate, properties, pwd, readFile, readTrusted, retry, script, sh, sleep, stage, stash, step, timeout, tool, unarchive, unstash, waitUntil, withContext, withDockerContainer, withDockerRegistry, withDockerServer, withEnv, wrap, writeFile, ws] or symbols [all, always, ant, antFromApache, antOutcome, antTarget, any, apiToken, architecture, archiveArtifacts, artifactManager, batchFile, booleanParam, buildButton, buildDiscarder, caseInsensitive, caseSensitive, choice, choiceParam, clock, cloud, command, configMapVolume, containerEnvVar, containerTemplate, cron, crumb, cucumber, defaultView, demand, disableConcurrentBuilds, docker, downloadSettings, downstream, dumb, emptyDirVolume, envVars, file, fileParam, filePath, fingerprint, frameOptions, freeStyle, freeStyleJob, git, hostPathVolume, hyperlink, hyperlinkToModels, installSource, jdk, jdkInstaller, jgit, jgitapache, jnlp, jobName, junit, label, lastDuration, lastFailure, lastGrantedAuthorities, lastStable, lastSuccess, legacy, list, local, location, logRotator, loggedInUsersCanDoAnything, masterBuild, maven, maven3Mojos, mavenErrors, mavenMojos, mavenWarnings, myView, nfsVolume, nodeProperties, nonStoredPasswordParam, none, overrideIndexTriggers, paneStatus, parameters, password, pattern, persistentVolumeClaim, pipeline-model, pipelineTriggers, plainText, plugin, projectNamingStrategy, proxy, queueItemAuthenticator, quietPeriod, run, runParam, schedule, scm, scmRetryCount, search, secretVolume, security, shell, slave, stackTrace, standard, status, string, stringParam, swapSpace, text, textParam, tmpSpace, toolLocation, unsecured, upstream, viewsTabBar, weather, zfs, zip] or globals [cache, currentBuild, docker, env, h, params, pipeline, runner, scm]
```

Is there some documentation missing regarding this, or is this a bug?