TypeError: Type must have a '[Symbol.iterator]()' method - JavaScript Iterator Implementation

To solve the issue 'Type must have a 'Symbol.iterator' method that returns an iterator.', you need to add an iterator method [Symbol.iterator]() to the Material object in the ComplexTrackOutMaterialsInput class.

Here's an example of how you can implement the iterator method for a Material object:

class Material {
  // Material properties and methods...

  // Implement the iterator method
  [Symbol.iterator]() {
    let index = 0;
    const materialEntries = Array.from(this.entries());

    return {
      next: () => {
        if (index < materialEntries.length) {
          const entry = materialEntries[index++];
          return { value: entry, done: false };
        } else {
          return { value: undefined, done: true };
        }
      }
    };
  }
}

Make sure to replace // Material properties and methods... with the actual properties and methods of the Material class.

Once you have added the iterator method to the Material class, the error should be resolved.