PsiTypeParameter (@NotNull String name, PsiClassType @NotNull [] superTypes) { @NlsSafe StringBuilder builder = new StringBuilder(); builder.append("def <").append(name); if (superTypes.length > 1 || superTypes.length == 1 && !superTypes[0].equalsToText(CommonClassNames.JAVA_LANG_OBJECT)) { builder.append(" extends "); for (PsiClassType type : superTypes) { if (type.equalsToText(CommonClassNames.JAVA_LANG_OBJECT)) continue; builder.append(type.getCanonicalText()).append(','); } builder.delete(builder.length() - 1, builder.length()); } builder.append("> void foo(){}"); try { return createMethodFromText(builder).getTypeParameters()[0]; } catch (RuntimeException e) { throw new IncorrectOperationException("type parameter text: " + builder); } }