Merge branch 'master' of https://github.com/SpineEventEngine/core-java …

…into fix-migrations

server/src/main/java/io/spine/server/entity/Repository.java

@@ -203,7 +203,7 @@ public final TypeUrl entityStateType() {
  public void registerWith(BoundedContext context) {
  checkNotNull(context);
  boolean sameValue = context.equals(this.context);
- if (this.context != null && !sameValue) {
+ if (hasContext() && !sameValue) {
  throw newIllegalStateException(
  "The repository `%s` has the Bounded Context (`%s`) assigned." +
  " This operation can be performed only once." +
@@ -222,14 +222,11 @@ public void registerWith(BoundedContext context) {
  }
 
  /**
- * {@inheritDoc}
- *
- * <p>Unlike, {@link #isOpen()}, once the repository is
- * {@linkplain #registerWith(BoundedContext) initialized}, this method always returns {@code true}.
+ * Tells if the repository is registered in a {@code BoundedContext}.
  */
  @Override
  public boolean isRegistered() {
- return context != null;
+ return hasContext();
  }
 
  /**
@@ -262,7 +259,7 @@ protected final boolean hasContext() {
  * if the repository has no context assigned
  */
  protected final BoundedContext context() {
- checkState(context != null,
+ checkState(hasContext(),
  "The repository (class: `%s`) is not registered with a `BoundedContext`.",
  getClass().getName());
  return context;
@@ -364,7 +361,7 @@ public void close() {
  */
  @Override
  public final boolean isOpen() {
- return context != null;
+ return hasContext();
  }
 
  @Internal