Class level variable in Singleton scope class

In class https://community.opengroup.org/osdu/platform/data-flow/enrichment/wks/-/blob/master/wks-core/src/main/java/org/opengroup/osdu/wks/util/RelationshipBlockHandler.java

@line 45 private String targetSchemaKindValue;

class variable is defined which is being initialized and used in multiple function within the class.

It may result in unexpected behavior.

Possible solution add scope prototype to the class.