code: public static Field getUniqeField(Object context,
  									  Class<? extends Annotation> annotation) {
  		
  		Set<Field> fields = FieldUtils.getAllFields(context, annotation);
  		
  		if(fields.isEmpty()) {
  			
  			return null;
  		}
  		else if(fields.size() > 1) {
  			
  			throw new DuplicateInjectionException(context.getClass(), annotation);
  		}
  		
  		return new ArrayList<Field>(fields).get(0);
  	}
docs: <p>Takes the target {@link Activity} and finds the <b>only</b>
  field which is marked for injection with the given annotation.</p>
  
  @param context
  the context whose {@link Field}s are to be scanned
  <br><br>
  @param annotation
  the {@link Class} of the {@link Annotation} to look for
  <br><br>
  @return the {@link Field} which is designated for injection
  <br><br>
  @throws DuplicateInjectionException
  when multiple fields exist with the given annotation
  <br><br>
  @since 1.0.0