package com.braintreepayments.api;

import androidx.annotation.Nullable;

public interface DropInResultCallback {
    /**
     * @param dropInResult {@link DropInResult}
     * @param error an exception that occurred while processing a DropInResult
     */
    void onResult(@Nullable DropInResult dropInResult, @Nullable Exception error);
}

package com.braintreepayments.api;

import androidx.annotation.Nullable;

/**
 * Callback for receiving the result of {@link DropInClient#deliverBrowserSwitchResult(FragmentActivity, DropInResultCallback)}
 */
public interface DropInResultCallback {
    /**
     * @param dropInResult {@link DropInResult}
     * @param error an exception that occurred while processing a DropInResult
     */
    void onResult(@Nullable DropInResult dropInResult, @Nullable Exception error);
}

Update Drop-In/src/main/java/com/braintreepayments/api/DropInResultCallback.java