import dependency and custom class

plugin.xml

@@ -24,6 +24,7 @@
         </config-file>
         <source-file src="src/android/SpectrumManager.java" target-dir="src/com/spoon/spectrum" />
         <source-file src="src/android/SpoonCameraExif.java" target-dir="src/com/spoon/spectrum" />
+        <framework src="com.google.code.findbugs:jsr305:3.0.2"></framework>
     </platform>
 
 	<!-- ios -->

src/android/SpectrumManager.java

@@ -17,6 +17,7 @@
 import java.io.IOException;
 import java.util.UUID;
 import androidx.exifinterface.media.ExifInterface;
+import com.spoon.spectrum.utils.ImageSize;
 
 public class SpectrumManager extends CordovaPlugin {
     @Override

src/android/utils/DoNotStrip.java

@@ -0,0 +1,23 @@
+package com.spoon.spectrum.utils;
+/*
+ *  Copyright (c) 2004-present, Facebook, Inc.
+ *
+ *  This source code is licensed under the MIT license found in the LICENSE
+ *  file in the root directory of this source tree.
+ *
+ */
+
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Add this annotation to a class, method, or field to instruct Proguard to not strip it out.
+ *
+ * <p>This is useful for methods called via reflection that could appear as unused to Proguard.
+ */
+@Target({ElementType.TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.CONSTRUCTOR})
+@Retention(CLASS)
+public @interface DoNotStrip {}

src/android/utils/ImageSize.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.spoon.spectrum.utils;
+
+import javax.annotation.concurrent.Immutable;
+
+/** Represents a rectangular area defined by its width and height. */
+@DoNotStrip
+@Immutable
+public class ImageSize {
+
+    /**
+     * Setting to 2**16 as this is the smallest common denominator for all common image libraries that
+     * we are interested in.
+     */
+    @DoNotStrip static final int MAX_IMAGE_SIDE_DIMENSION = 65536;
+
+    /** The size's width. */
+    @DoNotStrip public final int width;
+
+    /** The size's height. */
+    @DoNotStrip public final int height;
+
+    /**
+     * Creates a new {@link ImageSize}
+     *
+     * @param width Must be within [0, {@link #MAX_IMAGE_SIDE_DIMENSION}]
+     * @param height Must be within [0, {@link #MAX_IMAGE_SIDE_DIMENSION}]
+     */
+    @DoNotStrip
+    public ImageSize(final int width, final int height) {
+        Preconditions.checkArgument(width >= 0 && width <= MAX_IMAGE_SIDE_DIMENSION);
+        Preconditions.checkArgument(height >= 0 && height <= MAX_IMAGE_SIDE_DIMENSION);
+        this.width = width;
+        this.height = height;
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        final ImageSize that = (ImageSize) o;
+        return width == that.width && height == that.height;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = width;
+        result = 31 * result + height;
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "ImageSize{" + "width=" + width + ", height=" + height + '}';
+    }
+}

src/android/utils/Preconditions.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.spoon.spectrum.utils;
+
+import androidx.annotation.Nullable;
+
+/** Light-weight implementation for Precondition checks. */
+public final class Preconditions {
+
+    private Preconditions() {}
+
+    /**
+     * Asserts that the given reference is not null.
+     *
+     * @param reference A reference that might be null
+     * @return reference if reference is not <code>null</code>
+     * @throws NullPointerException if the given reference is <code>null</code>
+     */
+    public static <T> T checkNotNull(@Nullable final T reference) {
+        if (reference == null) {
+            throw new NullPointerException();
+        }
+        return reference;
+    }
+
+    /**
+     * Asserts that the given assertion about an argument is true.
+     *
+     * @param assertion The assertion to check
+     * @throws IllegalArgumentException if the given assertion is <code>false</code>
+     */
+    public static void checkArgument(final boolean assertion) {
+        if (!assertion) {
+            throw new IllegalArgumentException();
+        }
+    }
+
+    /**
+     * Asserts that the given assertion about a state is true.
+     *
+     * @param assertion The assertion to check
+     * @throws IllegalStateException if the given assertion is <code>false</code>
+     */
+    public static void checkState(final boolean assertion) {
+        if (!assertion) {
+            throw new IllegalStateException();
+        }
+    }
+}