Allows custom attributes to be added to the underlying context {@code Map} used to construct the
{@link Subject} instance.
<p/>
A {@code null} key{@link IllegalArgumentException}. A {@code null} value effectively removes
any previously stored attribute under the given key from the context map.
<p/>
<b>*NOTE*:</b> This method is only useful when configuring Shiro with a custom {@link SubjectFactory}
implementation. This method allows end-users to append additional data to the context map which the
{@code SubjectFactory} implementation can use when building custom Subject instances. As such, this method
is only useful when a custom {@code SubjectFactory} implementation has been configured.
@param attributeKey the key under which the corresponding value will be stored in the context {@code Map}.
@param attributeValue the value to store in the context map under the specified {@code attributeKey}.
@return this {@code Builder} instance for method chaining.
@throws IllegalArgumentException if the {@code attributeKey} is {@code null}.
@see SubjectFactory#createSubject(SubjectContext)
Allows custom attributes to be added to the underlying context {@code Map} used to construct the {@link Subject} instance. <p/> A {@code null} key{@link IllegalArgumentException}. A {@code null} value effectively removes any previously stored attribute under the given key from the context map. <p/> <b>*NOTE*:</b> This method is only useful when configuring Shiro with a custom {@link SubjectFactory} implementation. This method allows end-users to append additional data to the context map which the {@code SubjectFactory} implementation can use when building custom Subject instances. As such, this method is only useful when a custom {@code SubjectFactory} implementation has been configured.
@param attributeKey the key under which the corresponding value will be stored in the context {@code Map}. @param attributeValue the value to store in the context map under the specified {@code attributeKey}. @return this {@code Builder} instance for method chaining. @throws IllegalArgumentException if the {@code attributeKey} is {@code null}. @see SubjectFactory#createSubject(SubjectContext)