Returns the previous 'pre run as' identity of this {@code Subject} before assuming the current
{@link #runAs runAs} identity, or {@code null} if this {@code Subject} is not operating under an assumed
identity (normal state). See the {@link #runAs runAs} method for more information.
@return the previous 'pre run as' identity of this {@code Subject} before assuming the current
{@link #runAs runAs} identity, or {@code null} if this {@code Subject} is not operating under an assumed
identity (normal state).
@see #runAs
Returns the previous 'pre run as' identity of this {@code Subject} before assuming the current {@link #runAs runAs} identity, or {@code null} if this {@code Subject} is not operating under an assumed identity (normal state). See the {@link #runAs runAs} method for more information.
@return the previous 'pre run as' identity of this {@code Subject} before assuming the current {@link #runAs runAs} identity, or {@code null} if this {@code Subject} is not operating under an assumed identity (normal state). @see #runAs