Unable to create injector, see the following errors:

1) [Guice/DuplicateMapKey]: "first" and 1 other duplicate keys found in Map<String, String>.

Duplicates:
  Key: "first"
  Bound at:
    1 : DuplicateMapKeyErrorTest$MapModule.configure(DuplicateMapKeyErrorTest.java:32)
    2 : DuplicateMapKeyErrorTest$MapModule.configure(DuplicateMapKeyErrorTest.java:33)
    3 : DuplicateMapKeyErrorTest$ContributorModule.provideFirstIntoMap(DuplicateMapKeyErrorTest.java:47)

  Key: "second"
  Bound at:
    1 : DuplicateMapKeyErrorTest$ContributorModule.provideSecondIntoMap(DuplicateMapKeyErrorTest.java:53)
    2 : DuplicateMapKeyErrorTest$SecondContributorModule.provideSecondIntoMap(DuplicateMapKeyErrorTest.java:75)

MapBinder declared at:
  DuplicateMapKeyErrorTest$MapModule.configure(DuplicateMapKeyErrorTest.java:31)
      \_ installed by: DuplicateMapKeyErrorTest$MapModule -> RealMapBinder

1 error

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Full classname legend:
======================
DuplicateMapKeyErrorTest$ContributorModule:       "com.google.inject.errors.DuplicateMapKeyErrorTest$ContributorModule"
DuplicateMapKeyErrorTest$MapModule:               "com.google.inject.errors.DuplicateMapKeyErrorTest$MapModule"
DuplicateMapKeyErrorTest$SecondContributorModule: "com.google.inject.errors.DuplicateMapKeyErrorTest$SecondContributorModule"
RealMapBinder:                                    "com.google.inject.internal.RealMapBinder"
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End of classname legend:
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