Why does .getConstructor fail with a NoSuchMethodException despite zero-arg constructors existing for the class?

Processing Coding Questions
8

OK the version below works with inner classes so should solve the creation problem and access to Processing methods.

import java.lang.reflect.*;
import java.util.*;

GameCharacter player;

public void setup() {
  size(400, 300);
  player = new PlayerCharacter();
  player.addToInventory(this, VanillaIceCream.class);
  player.addToInventory(this, IceCream.class);
  // List players inventory
  player.printInventory();
}

public class GameCharacter {
  protected Inventory invt = new Inventory();
  public GameCharacter() {
  }
  public void addToInventory(PApplet papp, Class<? extends Ingredient> type) {
    invt.add(papp, type);
  }
  public void printInventory() {
    invt.printInventory();
  }
}

public class PlayerCharacter extends GameCharacter {

  public PlayerCharacter() {
  }
  // other methods...
}

public class Inventory {
  protected List<Ingredient> items = new ArrayList<Ingredient>();

  public Inventory() {
  }

  public void add(PApplet papp, Class<? extends Ingredient> type) {
    try {
      Ingredient ingredient = null;
      Class<?>[] innerClasses = papp.getClass().getDeclaredClasses();
      for (Class<?> innerClass : innerClasses) {
        if (innerClass == type) {
          Constructor<? extends Ingredient> cstr = type.getDeclaredConstructor(papp.getClass());
          ingredient = cstr.newInstance(papp);
          break;
        }
      }
      // do stuff with ingredient
      items.add(ingredient);
    }
    catch (NoSuchMethodException e) {
      e.printStackTrace();
      println("Constructor not available: " + e.getMessage());
    }
    catch (IllegalAccessException e) {
      println("Constructor can not be accessed: " + e.getMessage());
    }
    catch (InvocationTargetException e) {
      println("Exception in constructor: " + e.getCause().getMessage());
    }
    catch (InstantiationException e) {
      println("Class cannot be instantiated: " + e.getMessage());
    }
  }

  public void printInventory() {
    for (Ingredient item : items)
      item.print();
  }
}

public class Ingredient {
  public Ingredient() {
  }
  public void print() {
    println("Ingredient");
  }
  // other methods
}

public class IceCream extends Ingredient {
  IceCream() {
  }
  public void print() {
    println("Icecream");
  }
}

public class VanillaIceCream extends IceCream {
  VanillaIceCream() {
  }
  public void print() {
    println("Vanilla Icecream");
  }
}
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