setEvalscript(evalscript) {
    let script;
    if (typeof evalscript === 'string') {
      script = evalscript;
    } else {
      try {
        script = serializeEvalscript(evalscript);
      } catch (error) {
        this.error_ = error;
        this.setState('error');
        return;
      }
    }
    this.evalscript_ = script;
    this.fireWhenReady_();
  }
Set or update the Evalscript used to process the data.  Either a process object or a string
Evalscript can be provided.  If a process object is provided, it will be serialized to produce the
Evalscript string.  Because these functions will be serialized and executed by the Processing API,
they cannot refer to other variables or functions that are not provided by the Processing API
context.

@param {Evalscript|string} evalscript The process to apply to the input data.
@api