core/src/com/google/inject/spi/DependencyAndSource.java
public String getBindingSource() {
    if (source instanceof Class) {
      return StackTraceElements.forType((Class) source).toString();
    } else if (source instanceof Member) {
      return StackTraceElements.forMember((Member) source).toString();
    } else {
      return source.toString();
    }
  }
public String getBindingSource() {
    if (source instanceof Class) {
      return StackTraceElements.forType((Class) source).toString();
    } else if (source instanceof Member) {
      return StackTraceElements.forMember((Member) source).toString();
    } else {
      return source.toString();
    }
  }
Returns a string describing where this dependency was bound. If the binding was just-in-time,
there is no valid binding source, so this describes the class in question.