package com.reason.lang.core.psi;

import com.intellij.psi.NavigatablePsiElement;
import com.intellij.psi.StubBasedPsiElement;
import com.reason.lang.core.stub.ModuleStub;

import javax.annotation.Nullable;

public interface PsiModule extends PsiNamedElement, NavigatablePsiElement, PsiStructuredElement, StubBasedPsiElement<ModuleStub> {
    @Nullable
    PsiScopedExpr getModuleBody();
}

package com.reason.lang.core.psi;

import com.intellij.psi.NavigatablePsiElement;
import com.intellij.psi.StubBasedPsiElement;
import com.reason.lang.core.stub.ModuleStub;
import org.jetbrains.annotations.Nullable;


public interface PsiModule extends PsiNamedElement, NavigatablePsiElement, PsiStructuredElement, StubBasedPsiElement<ModuleStub> {
    @Nullable
    PsiScopedExpr getModuleBody();
}

Fix Nullable import