default boolean isLazy() {
    return false;
  }
Returns whether this context source is lazy. A lazy context source may return {@linkplain Entries#EMPTY} from
{@linkplain #getEntries()} in case the {@code getEntries()} implementation would be too slow. This may come at a
small runtime cost.

<p>Only libraries can be lazy. This method has no effect on sources.</p>

@return true if this context source is lazy, false otherwise
src/org/jetbrains/java/decompiler/main/extern/IContextSource.java